Surface light source device and liquid crystal display device

Abstract

In a surface light source device including: a light source section having a light emitting face; an optical panel arranged so as to cover the light emitting face; and a at least one frame having a front face portion that covers the peripheral portion of the light emitting face, the at least one frame is composed of a plurality of divisional members connected with each other and a light shielding portion is provided at each slit between the divisional members in the front face portion of the at least one frame. Whereby, light from the light source section is prevented from leaking through each slit between the divisional members in the front face portion of the at least one frame.

1. A surface light source device, comprising:
 a light source section which has a light emitting face;   an optical panel which is arranged so as to cover the light emitting face of the light source section and which performs a predetermined optical operation for light from the light source section; and   at least one frame which includes a front face portion arranged so as to overlap with a peripheral portion of the optical panel in a direction of a thickness of the optical panel and a side face portion extending from an outer periphery of the front face portion toward the light source section and which is arranged along a peripheral portion of the light emitting face of the light source section;   wherein the at least one frame is composed of a plurality of divisional members divided in a direction along the peripheral portion of the light emitting face of the light source section, which have a slit between each divisional member, and   a light shielding portion is provided, at each said slit in the front face portion of the frame, for preventing light of the light source section from leaking through each said slit,   wherein the divisional members include a u-shaped member, and   wherein the corner portion of the u-shaped member is formed by drawing.   
     
     
       2. The surface light source device of  claim 1 , wherein
 the at least one frame serves as a rear frame of which front face portion is provided on the light source section side of the peripheral portion of the optical panel so as to cover the peripheral portion of the light emitting face of the light source section.   
     
     
       3. The surface light source device of  claim 1  wherein
 the at least one frame serves as a front frame of which front face portion is provided on a side opposite the light source section side of the peripheral portion of the optical panel so as to cover the peripheral portion of the light emitting face of the light source section. 
 
     
     
       4. The surface light source device of  claim 1 , wherein
 the at least one frame includes:   a rear frame of which front face portion is provided on the light source section side of the peripheral portion of the optical panel so as to cover the peripheral portion of the light emitting face of the light source section; and   a front frame of which front face portion is provided on a side opposite the light source section side of the peripheral portion of the optical panel so as to cover the peripheral portion of the light emitting face of the light source section.   
     
     
       5. The surface light source device of  claim 1 , wherein
 the connection between the plural divisional members are carried out by welding, and   the light shielding portion is formed of a welded portion formed by the welding.   
     
     
       6. The surface light source device of  claim 5 , wherein
 the welded portion is formed at each slit between the plural divisional members in the side face portion, in addition to each slit between the plural divisional members in the front face portion.   
     
     
       7. A liquid crystal display device, comprising a surface light source device according to any one of  claims 2 ,  3 ,  4 ,  5 ,  6  and  1 , wherein
 the optical panel serves as a liquid crystal display panel including a pair of transparent substrates and a liquid crystal layer disposed between the pair of transparent substrates, and 
 the light source section serves as a backlight section for emitting light to the liquid crystal display panel. 
 
     
     
       8. A surface light source device, comprising:
 a light source section which has a light emitting face;   a liquid crystal display panel which is arranged so as to cover the light emitting face of the light source section; and   at least one frame which includes a front face portion arranged so as to overlap with a peripheral portion of the liquid crystal display panel in a direction of a thickness of the liquid crystal display panel and a side face portion extending from an outer periphery of the front face portion toward the light source section;   wherein the at least one frame is composed of a plurality of divisional members, said at least one frame has a slit between each divisional member, and   a light shielding portion is provided, at said slit in the front face portion of the frame, for preventing light of the light source section from leaking through said slit,   wherein the plurality of divisional members are connected by welding, and the light shielding portion is formed by a welded portion formed by the welding,   wherein the divisional members include a first and a second divisional member each having two corner portions that include two outside corner portions at an outermost edge of the divisional member and wherein each of the two outside corner portions respectively extend around two corners of a peripheral edge portion of the liquid crystal display panel, and   wherein the light shielding portion provided in said slit is arranged in an entire region in a widthwise direction across the front face portion of the frame,   wherein the at least one frame serves as a front frame of which front face portion is provided on a side opposite the light source section side of the peripheral portion of the liquid crystal panel,   wherein the slits have a step-like cross-sectional shape that further prevents light of the light source section from leaking through the slits.   
     
     
       9. The surface light source device of claim 8, wherein the welded portion is formed at each slit between the plural divisional members in the side face portion, in addition to each slit between the plural divisional members in the front face portion. 
     
     
       10. The surface light source device of claim 8, wherein the two corner portions of the first and second divisional members are formed by a drawing process. 
     
     
       11. The surface light source device of claim 8, wherein the divisional member further includes a third and fourth divisional member each having a straight shape,
 wherein the first and second divisional members are provided on a longitudinal side of the frame and the third and fourth divisional members are provided on a lateral side of the frame.   
     
     
       12. A surface light source device, comprising:
 a light source section which has a light emitting face;   a liquid crystal display panel which is arranged so as to cover the light emitting face of the light source section; and   a front frame which includes a first front face portion arranged so as to be provided on a side opposite the light source section side of the peripheral portion of the liquid crystal display panel and a first side face portion extending from an outer periphery of the first front face portion toward the light source section;   a rear frame which includes a second front face portion arranged so as to be provided on the light source section side of the peripheral portion of the liquid crystal display panel and a second side face portion extending from an outer periphery of the second front face portion toward the light source section,   wherein each of the front frame and the rear frame is respectively composed of a plurality of divisional members respectively dividing the front and rear frames in a direction along the peripheral portion of the liquid crystal display panel, which have a slit between each divisional member, and   a light shielding portion is provided, at said slit in each of the first front face portion of the front frame and the second front face portion of the rear frame, for preventing light of the light source section from leaking through said slit,   wherein the plurality of divisional members are connected by welding, and the light shielding portion is formed of a welded portion formed by the welding,   wherein the divisional members for the front frame include a first and second divisional member each having two corner portions that include two outside corner portions at an outermost edge of the divisional member and wherein each of the two outside corner portions respectively extend around two corners of a peripheral edge portion of the liquid crystal display panel,   wherein the light shielding portion provided in said slit is arranged in an entire region in a widthwise direction across the first front face portion of the front frame and the second front face portion of the rear frame, and   wherein the rear frame slits are offset relative to the front frame slits in a longitudinal direction of the divisional members to further prevent light of the light source section from leaking through the front frame slits.   
     
     
       13. The surface light source device of claim 12, wherein the two corner portions of the first and second divisional members are formed by a drawing process. 
     
     
       14. The surface light source device of claim 12, wherein the welded portion is formed at each slit between the plural divisional members in the first and second side face portions, in addition to each slit between the plural divisional members in the first and second front face portions. 
     
     
       15. The surface light source device of claim 12, wherein the divisional member for the front frame further includes a third and fourth divisional member each having a straight shape,
 wherein the first and second divisional members are provided on a longitudinal side of the front frame and the third and fourth divisional members are provided on a lateral side of the front frame.   
     
     
       16. A liquid crystal display device, comprising a surface light source device according to any one of claims 8 and 12, wherein
 the liquid crystal display panel includes a pair of transparent substrates and a liquid crystal layer disposed between the pair of transparent substrates, and   the light source section serves as a backlight section for emitting light to the liquid crystal display panel.