Minebea Company, Limited

Koichi Toyoda

Shingo Suzuki

Masafumi Okada

Takashi Ishii

Motoji Egawa

Takahiro Shimura

Yoshiki Nakamura

The present invention provides a spread illuminating apparatus which can ensure uniform brightness over its entire screen. A light reflection-diffusion layer is formed on a light conductive member at a face provided with an optical path conversion means. Light emitted from spot-like light sources is reflected efficiently by the light reflection-diffusion layer toward a transparent substrate, and light intensity degrades in a substantially linear manner with the increase in distance from respective spot-like light sources. Sharp change of brightness on an observation surface can be prevented due to the light intensity degrading linearly.

Spread illuminating apparatus with light reflection-diffusion layer on optical path conversion means

There is provided a spread illuminating apparatus which is improved in terms of compactness. A light guiding member ( ) provided with a curve ( ) is disposed between an end ( ) of a light conductive member ( ) and a spot-like light source ( ). Light beams from the spot-like light source ( ) which travel in the direction orthogonal to an electric wiring board ( ) are directed toward the end ( ) of the light conductive member ( ) (in the direction parallel with the electric wiring board ( )) to be properly guided while reflected at the curve ( ). Since the light beams from the spot-like light source ( ) are properly guided, the light beams from the spot-like light source ( ) can enter the light conductive member ( ) with the spot-like light source ( ) and the light conductive member ( ) not disposed on the same plane. Therefore, the spot-like light source ( ) can be arranged with less restrictions, thereby enabling the spot-like light source ( ) to be disposed on the electric wiring board ( ) together with other electronic components. Accordingly, in comparison with the conventional art in which the spot-like light source can not be disposed on the electric wiring board together with other electronic components requiring separate circuits to be provided, the apparatus can be improved in terms of compactness.

Spread illuminating apparatus

There is provided a spread illuminating apparatus to improve a coupling efficiency between a light conductive member and a spot-like light source. A claw ( ) of an upper frame ( ) is fitted to a recess ( ) of an LED ( ), and generates a spring force in a direction of a light conductive member ( ) (a spring force in a longitudinal direction of the light conductive member ( )) in a fitted condition to press the LED ( ) toward the light conductive member ( ). Thus, the light conductive member ( ) and the LED are excellently and tightly attached to each other, and surely positioned, and the coupling efficiency of the light conductive member ( ) with the LED is excellent. Since the claw ( ) of the upper frame is fitted to the recess ( ) in the LED ( ), deviation of the LED ( ) in a direction orthogonal to the longitudinal direction of the light conductive member ( ) is suppressed, and the light conductive member ( ) and the LED ( ) can be surely positioned accordingly, and the coupling efficiency of the light conductive member ( ) with the LED ( ) can be further improved.

There is provided a spread illuminating apparatus to improve the coupling efficiency between members constituting a light source. The light source comprises a bar-like light conductive member and spot-like light sources. The spot-like light sources are mounted and soldered on an FPC, the light conductive member is fitted between the spot-like light sources, and ends of the light conductive member face light emitting surfaces of the spot-like light sources. The FPC has a deformed portion shaped U and forming an open area. An elastic force is generated in the longitudinal direction when the open area is expanded, by inserting the light conductive member whose length is larger than a distance between the spot-like light sources, between the spot-like light sources. This elastic force makes the light emitting surfaces of the spot-like source press on the ends of the light conductive member, and the coupling efficiency therebetween is improved.

Spread illuminating apparatus with printed circuit board having elastic force

There is provided an FPC for mounting components with an improved workability of fitting into other components. Both a second bend ( ) and a third bend ( ) are provided with a copper foil(s) ( ). The copper foil ( ) provided at each bend functions as a core material to be plastically transformed when the respective bends ( ) are formed and to prevent an FPC ( ) from rebounding due to elastic recovery, thereby enabling the bends to retain their shape as desired. As shown in the figure, in case there are a plurality of bends, the copper foil ( ) extends to be disposed at all the bends, thereby avoiding the deterioration in workability of assembly, which is invited due to the FPC ( ) rebounding. Further, after assembling the FPC ( ), a cover portion ( ) does not rebound with time within the other components and does not shift off a predetermined position.

FPC for mounting components and spread illuminating apparatus using the same

In the spread illuminating apparatus in which the light emitted from the light emitting diode , which is disposed close to the transparent substrate , is made to be emitted toward the viewing direction of the transparent substrate , the groove is provided on the transparent substrate in such a manner as it crosses orthogonally light emitted in a radial direction from the light emitting diode so that most light beams , , can be emitted toward the viewing direction. Since the light beams , and progress in the viewing direction through the groove , an amount of light turning aside to no purpose can be reduced.

There is provided a spread illuminating apparatus to suppress the appearance of moir&eacute; fringes. A light reflection pattern of a transparent substrate is composed of grooves of substantially triangular in section and flat portions adjacent thereto. The light reflection pattern is formed substantially parallel to the optical axis of a bar-like light source and the depth of the grooves increases gradually in proportion to the increase in distance from the light source. The interval of the adjacent grooves (the groove interval) is set to vary irregularly. Thereby, the relation between the interval of grooves and the interval of mosaic pattern of liquid crystal cells is not definite, and the appearance of moir&eacute; pattern can be suppressed. The variation ratio of the groove interval is set to range 25% to 85% of the average groove interval

Spread illuminating apparatus with irregular interval of grooves of light reflection pattern

There is provided a spread illuminating apparatus to improve a light coupling efficiency between a light conductive member and a transparent substrate. In the spread illuminating apparatus, an FPC mounting section of a frame is set to be lower than a substrate mounting section by the thickness of an FPC, and an extension provided at an FPC main body is let through an opening formed at a stepped part of the frame so as to be disposed on a reverse side of the frame, whereby an upper surface of the light conductive member is adapted to be flush with an upper surface of the transparent substrate while prevention of the deviation in the thickness direction between the light conductive member and the transparent substrate is not obstructed even when the extension is provided, which results in improving the light coupling efficiency.

Spread illuminating apparatus including frame with two sections stepped

A frame for use with a spread illuminating apparatus having a first facing plate, a second facing plate and a light reflecting portion. The frame being capable of covering and positioning a light source adjacent to an end of a transparent substrate by positioning the light source and the transparent substrate between the first and second facing plate. The frame futher including end portions of the first and second facing plates that are configured to resiliently clamp a portion of the transparent substrate. Productivity being improved and apparatus being made compact due to reduced number of parts and assembling processes. Uniformity of brightness and darkness being presented due to elimination of application of tape.

Spread illuminating apparatus with a frame having resilience for clamping constituent members

There is provided a spread illuminating apparatus ensuring excellent light utilization efficiency without deteriorating workability in assembling. A first extension plate and a second extension plate, which are bent so as to have a spring force working toward each other, are provided on an upper opposing plate of a frame. A spot-like light source and a light conductive member are pressed by means of the spring force of the above extension plates. A clearance between the spot-like light source and the first extension plate, and a clearance between the light conductive member and the second extension plate are eliminated, whereby generation of play can be prevented resulting in an improvement of workability in assembling. Also, the spot-like light source and the light conductive member contact tightly with each other eliminating a clearance therebetween so as to improve light utilization efficiency. The frame and further the whole apparatus can be compact while maintaining a high accuracy.

Spread illuminating apparatus with a frame having a spring force

A spread illuminating apparatus radiating heat generated by a spot-like light source. The apparatus includes a metal enclosure ( ) integrally formed at an end of a metal frame ( ) so as to enclose a cover portion ( ) which receives a spot-like light source ( ) and dummy patterns ( ) provided on inner surfaces of the first, second and third face portions ( ) of the cover portion ( ). The enclosure ( ) functions as a heat sink and conducts heat generated by the spot-like light source ( ) outwardly for radiation. Heat is conducted owing to the dummy patterns ( ).

Spread illuminating apparatus having heat sink function

According to the strength of the leak light from the spot-like light source the light diffusion film the light diffusion co-efficient is changed is disposed between the flat transparent substrate and the light source portion Thereby, by diffusing the strength of the leak light, the incident light to the one side end face of the resin substrate is made approximately even, and the direct entering of the leak light into the flat transparent substrate is suspended and thereby the generation of the bright line is suspended to realize an even and spread illumination.

Spread illumination apparatus

A light reflection member for covering a light conductive member is provided with a claw . The claw is a positioning means for setting the light conductive member to a transparent substrate The positional relation between the transparent substrate and the light conductive member is ensured by this claw , whereby the assembling of a spread illuminating apparatus is made easier, the positional shifting between the members due to aging is prevented and a desired brightness of the spread illuminating apparatus is secured.

Spread illuminating apparatus with means for positioning transparent substrate

There is provided a spread illuminating apparatus in which transmission efficiency of light is enhanced and in which a good liquid crystal display screen is provided. Positioning means ( ) are provided on a lower plate inner surface ( ) of a frame ( ) that covers a light conductive member ( ). The positioning means ( ) push up the light conductive member ( ) relative to a transparent substrate ( ) in the direction of the thickness of the light conductive member ( ) (light source ( )) (toward an upper plate inner surface ( ) of the frame) by the thickness t of a reflection preventive film ( ) attached to the lower surface of the transparent substrate ( ). Thus, an exit surface ( ) of the light conductive member ( ) does not overlap the reflection preventive film ( ), and a good display can be realized on the liquid crystal screen. Further, the exit surface ( ) of the light conductive member ( ) and an incident surface ( ) of the transparent substrate ( ) can be fixedly held at the same height position, and thus light can be transmitted efficiently.

Spread illuminating apparatus with means for positioning a bar-like light source

A cover portion which covers a spot-like light source is provided on the printed circuit board (FPC) , thereby giving electrical insulation from the surrounding. Therefore, even if a metallic frame is disposed close to the spot-like light source , the spot-like light source is prevented surely from shortcircuiting with the metallic frame. Since the cover portion covers the surrounding of the spot-like light source , light leakage from the spot-light like source can be minimized and light emitted from the spot-like light source can be used efficiently.

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Iwata-gun, Japan

Koichi Toyoda