CN100576033C - Back light unit - Google Patents
Back light unit Download PDFInfo
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- CN100576033C CN100576033C CN200510135811A CN200510135811A CN100576033C CN 100576033 C CN100576033 C CN 100576033C CN 200510135811 A CN200510135811 A CN 200510135811A CN 200510135811 A CN200510135811 A CN 200510135811A CN 100576033 C CN100576033 C CN 100576033C
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- light
- optical plate
- light source
- incidence surface
- blu
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Abstract
The present invention relates to back light unit.Especially, the present invention relates to increase the back light unit of light collection efficiency.Back light unit according to the present invention comprises: light source cell; Optical plate is used for the light from light source incident being changed and launching into surface light, and has the device that is used to prevent to face the light loss on the incidence surface of light source cell; And prismatic lens, it is positioned on the upper surface of optical plate, and each prism facets is to optical plate.Preferably, on incidence surface, saliently be formed for preventing the device of light loss, or the form with prism forms on incidence surface towards light source cell.And, preferred, be used to prevent that the device of light loss from being the Fresnel lens that is attached on the incidence surface.Preferably, be used to prevent that the device of light loss has crooked inclined surface.Back light unit further comprises the reflector plate on the lower surface that is positioned at optical plate, with the light of reflection from the optical plate emission.
Description
Technical field
The present invention relates to back light unit, especially, the present invention relates to increase the back light unit of light collection efficiency.
Background technology
Liquid crystal display device (after this, " LCD equipment ") is the electric equipment that changes over viewdata from the electric data that many devices produced, and according to the voltage that applies, transmits them by the variation of using the crystal transmissivity.
LCD equipment is a kind of equipment that is used for display message, but itself does not have light source.Therefore, LCD equipment needs extra equipment so that illuminate the whole screen of LCD equipment equably by the light source on the back side that is installed in LCD equipment.As such extras, using provides the back light unit of light to the screen of LCD (after this, being called " BLU ").
According to the position of the installation of cold-cathode fluorescence lamp (after this, being called " CCFL "), BLU is classified into direct projection illumination type and edge light type.In the BLU of direct light type, lamp is disposed under the liquid crystal board, and in edge light type BLU, lamp is disposed on the side of optical plate.
Fig. 1 has schematically shown the sectional view of the BLU of LCD equipment.
Fig. 1 has shown the BLU 100 of edge light type.The BLU 100 of edge light type comprises light source cell 110, optical plate 120, reflector plate 130 and optical thin film 140.
Optical thin film 140 comprises diffusion sheet 142, prismatic lens 144, screening glass 146 and polarization by reflection film 148.Polarization by reflection film 148 is available.
The function of each element in the explained later optical thin film 140.
Evenly be scattered in the light process diffusion sheet 142 in the optical plate 120.The light of optical plate 120 has been passed through in diffusion sheet 142 scatterings or gathering, and all even visible angle becomes wideer so that brightness becomes.
Yet the brightness of the light of process diffusion sheet 142 is considerably reduced.For addressing this problem, use prismatic lens 144.The light of diffusion sheet 142 has been passed through in prismatic lens 144 refraction, and assembles with low angle and incide light on the direction that is basically perpendicular to prismatic lens 144, so that increase the brightness in effective visible angle.
Be arranged in LCD equipment (not shown) on the optical thin film 140 and only have characteristic by the light that comes out from optical thin film 140 of a part.For example, compressional wave (P-ripple) passes through, and shear wave (S-ripple) is absorbed.Therefore, arrange that polarization by reflection film 148 uses the shear wave of absorption.
Polarization by reflection film 148 is the direction that is reflexed to optical plate 120 by the shear wave in the light of screening glass 146 scatterings (S-ripple), and compressional wave (P-ripple) is offered LCD equipment (not shown).
By optical plate 120 or reflector plate 130 with the shear wave of reflection secondary reflection again.To be changed be the light that comprises compressional wave and shear wave to the shear wave of reflection through reflection again.The light process diffusion sheet 142 that changes, prismatic lens 144 and screening glass 146, and enter polarization by reflection film 148 once more.Therefore, by above-mentioned processing, BLU 100 can increase the efficient of light.
In Fig. 1, arrange the prism of prismatic lens 144 towards screening glass 146.Yet in order to increase the light service efficiency, the prism of prismatic lens 144 can be arranged (adverse prism sheet) towards diffusion sheet 142.
Have in the planar light source unit of adverse prism sheet in U.S. Patent No. 5126882 BLU disclosed and shown in Figure 1, the incidence surface of optical plate 120 is perpendicular to the upper surface of optical plate 120.
In this BLU, the incidence surface of optical plate 120 is perpendicular to the upper surface of optical plate 120, and therefore when the light that comes out from light source 112 passed through the incidence surface of optical plate 120, brightness was considerably reduced.
Summary of the invention
The purpose of this invention is to provide a kind of back light unit (BLU), it can prevent the loss of the light that comes out from light source, to solve because the caused above-mentioned problem of shape of the incidence surface of optical plate.
BLU according to the present invention comprises: light source cell; Optical plate is used for the light from light source incident being changed and launching into surface light, and has the device that is used to prevent to face the light loss on the incidence surface of light source cell; And prismatic lens, it is positioned on the upper surface of optical plate, and each prism facets is to optical plate.
Preferably, on incidence surface, saliently be formed for preventing the device of light loss, or form with the form of prism towards light source cell.And, preferred, be used to prevent that the device of light loss from being the Fresnel lens that is attached on the incidence surface.
Preferably, be used to prevent that the device of light loss has crooked inclined surface.
BLU further comprises the reflector plate on the lower surface that is positioned at optical plate, with the light of reflection from the optical plate emission.
By forming the incidence surface of that tilt and/or crooked optical plate, can be added to the area of reflective surface according to BLU of the present invention.In addition, the incidence surface of the optical plate by forming prism shape, or on incidence surface, adhere to Fresnel lens, can be added to the area of reflective surface according to BLU of the present invention.Therefore, increased the efficient that light is assembled, and the brightness that has improved display device.
Description of drawings
Fig. 1 is a sectional view, and it has shown the relation that is arranged in light source, optical plate, optical thin film and reflector plate in the edge light type back light unit;
Fig. 2 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to first embodiment of the invention;
Fig. 3 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to second embodiment of the invention;
Fig. 4 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to third embodiment of the invention;
Fig. 5 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to fourth embodiment of the invention;
Fig. 6 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to fifth embodiment of the invention;
Fig. 7 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to sixth embodiment of the invention; With
Fig. 8 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to seventh embodiment of the invention.
Embodiment
To more be expressly understood the present invention by detailed description in conjunction with following accompanying drawing.
In BLU according to the present invention, the function of reflector plate and optical thin film and structure are identical with BLU's shown in Figure 1.Therefore, omit identical explanation.
In BLU according to the present invention, can use adverse prism sheet that each prism wherein arranges towards diffusion sheet to increase the light service efficiency.And, only by using light source cell and optical plate to explain each embodiment.
Fig. 2 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to first embodiment of the invention.
As mentioned above, light source 110 comprises light source reflector 114 and the light source 112 that is installed on the light source reflector 114.
The incidence surface 202 of facing the optical plate 201 of light source cell 110 is the spherical surfaces that form towards light source 112 projections, or wherein radius curve is different aspheric surface.Therefore, increased the area of the incidence surface 202 that the light that produces from light source 112 enters, and therefore when light is assembled, reduced light loss.
Fig. 3 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to second embodiment of the invention.The incidence surface 302 of facing the optical plate 301 of light source cell 110 has prism.
Than flat incidence surface, in prismatic shape incidence surface 302, the area that light enters is maximized, and therefore can significantly reduce light loss.The angle of each prism that is formed into reflective surface 302 is unrestricted, but preferred angle is 90 °.
Fig. 4 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to third embodiment of the invention.The incidence surface of facing the optical plate 401 of light source cell 110 is provided with Fresnel lens 403.
Usually, Fresnel lens 403 has two films.Flat outside film refract light, and the internal membrane of lens-type or prism-type transmits light uniformly.Therefore, by Fresnel lens 403, a direction, launch from the light that light source 112 produces.
Fig. 5 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to fourth embodiment of the invention.
The optical plate that is different from BLU shown in Figure 1 is not orthogonal to the upper surface of optical plate 501 according to the incidence surface 502 of the optical plate 501 of the BLU of the 4th embodiment, but tilts to the opposite side of light source 112.
In optical plate shown in Figure 5 501, the angle between incidence surface 502 and the upper surface (α) is less than 90 °.Therefore, the area of incidence surface 502 is greater than the area of the incidence surface of optical plate shown in Figure 1 102.
Fig. 6 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to fifth embodiment of the invention.
As the 4th embodiment, the incidence surface 602 of optical plate 601 shown in Figure 6 tilts, and the surface of incidence surface 602 is crooked.
Fig. 7 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to sixth embodiment of the invention.
Incidence surface 702 according to the optical plate 701 of the BLU of the 6th embodiment is not orthogonal to the upper surface of optical plate 701, but tilts to light source 112.
In optical plate shown in Figure 7 701, the angle between incidence surface 702 and the upper surface (β) is greater than 90 °.Therefore, the area of incidence surface 702 is greater than the area of the incidence surface of optical plate shown in Figure 1 102.
Fig. 8 is a sectional view, and it has partly shown light source and the optical plate of arranging among the BLU according to seventh embodiment of the invention.
The incidence surface 802 of optical plate 801 shown in Figure 8 tilts as the 6th embodiment, and the surface of incidence surface 802 is crooked.
According to a preferred embodiment of the invention, it should be noted that various modifications and changes may be made according to above-mentioned instruction those of ordinary skill in the art.Therefore, should be understood that in the scope and spirit of the present invention that do not break away from the claims qualification, can make change specific embodiment of the present invention.
Claims (2)
1. back light unit comprises:
Light source cell;
Optical plate is used for the light from light source incident being changed and launching into surface light, and has the device that is used to prevent to face the light loss on the incidence surface of light source cell; With
Prismatic lens, it is positioned on the upper surface of optical plate, and each prism facets is to optical plate,
Wherein this is used to prevent that the device of light loss from being the Fresnel lens that is attached on the incidence surface.
2. according to the back light unit of claim 1, further comprise:
Reflector plate, it is positioned on the lower surface of optical plate, with the light of reflection from the optical plate emission.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020050096842 | 2005-10-14 | ||
| KR1020050096844 | 2005-10-14 | ||
| KR20050096842 | 2005-10-14 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1949051A CN1949051A (en) | 2007-04-18 |
| CN100576033C true CN100576033C (en) | 2009-12-30 |
Family
ID=38018614
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200510135811A Expired - Fee Related CN100576033C (en) | 2005-10-14 | 2005-12-23 | Back light unit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100576033C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104459867A (en) * | 2013-09-23 | 2015-03-25 | 纬创资通股份有限公司 | Light guide plate and backlight module |
| CN108287389A (en) * | 2018-02-24 | 2018-07-17 | 京东方科技集团股份有限公司 | Backlight module and display device |
-
2005
- 2005-12-23 CN CN200510135811A patent/CN100576033C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1949051A (en) | 2007-04-18 |
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| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20091230 Termination date: 20181223 |