CN201107516Y

CN201107516Y - Side light type back light module unit

Info

Publication number: CN201107516Y
Application number: CNU2007200759883U
Authority: CN
Inventors: 崔品静
Original assignee: SVA Group Co Ltd
Current assignee: SVA Group Co Ltd
Priority date: 2007-11-26
Filing date: 2007-11-26
Publication date: 2008-08-27
Anticipated expiration: 2017-11-26

Abstract

The utility model discloses a lateral light type backlight module of an LCD. The lateral light type backlight module includes a light guiding plate; two groups of cold cathode florescent lamps that are respectively arranged at two sides of the light guiding plate; two lighting tube reflection hoods that are respectively arranged surrounding the two groups of cold cathode florescent lamps and each of which includes a bottom surface for the reflection hood, a side surface for the reflection hood and a top surface for the reflection hood to surround the three surfaces of the cold cathode florescent lamps; a reflection sheet arranged below the light guiding plate; a back plate arranged below the reflection sheet; the positions on the bottom surface, the side surface and the top surface for the reflection hood corresponding to the cold cathode florescent lamps respectively bend outwards to the direction deviating the cold cathode florescent lamps to form a groove of the bottom surface, a groove of the side surface and a groove of the top surface. The lateral light type backlight module of the utility model effectively reduces the induction current generated by the parasitic capacitance between the reflection hoods and the lighting tubes and ensures the lighting efficiency of the lighting tubes and the illumination uniformity of the two ends of the lighting tubes.

Description

Side-light type module backlight

Technical field

The utility model relates to a kind of side-light type module backlight of LCD, particularly a kind ofly can effectively reduce the side-light type module backlight that produces faradic LCD owing to stray capacitance.

Background technology

In present information society, it is more and more important that electronic display unit becomes, so electronic display unit is used on the various products.In addition, in order to satisfy the information society that is showing improvement or progress day by day, the electronic display unit of new function is invented.Usually electronic display unit provides information for the mankind, and electronic display unit is transformed into light signal to the electric signal from various electronic equipment outputs and is seen reception by people, and electronic display unit is the middle bridge of linking up of human and electronic equipment.

Electronic display unit has two kinds: active and passive type, active electronic display unit mainly comprise CRT (cathode ray tube; Cathode-ray tube (CRT)) display, PDP (plasmadisplay panel; Plasma display), OELD (organic electroluminescentdisplay; Display of organic electroluminescence), LED (light emitting diode; Light emitting diode) display etc.The passive-type electronic display unit mainly comprises LCD (LCD), EPID (electrophoretic image display; Electrophoretic display device (EPD)) etc.

In recent years, because that LCD equipment has a volume is little, frivolous, advantages such as low power consuming have obtained very big development.Because LCD equipment is the passive type electronic display unit, it needs a module backlight to provide brightness with displayed image again, and module backlight is divided into straight-down negative and side-light type again according to the position difference of light source.

Fig. 1 is the schematic cross-section of present a kind of side-light type module backlight, two fluorescent tubes 13 provide light source, reflex housing 4 three bread enclose fluorescent tube 13, make light that fluorescent tube 13 sends to the direction outgoing that does not have to surround, can produce stray capacitance C1 between fluorescent tube 13 and the reflex housing 14, C2 and C3, stray capacitance C1 result between the bottom surface 41 of fluorescent tube 13 and reflex housing 14, stray capacitance C2 results between the side 42 of fluorescent tube 13 and reflex housing 14, and stray capacitance C3 results between the end face 43 of fluorescent tube 13 and reflex housing 14.When a high-tension electricity is added on the fluorescent tube 13, owing to there is stray capacitance C1, C2, C3 and produce induction current, and the phase place of induction current and driving high-tension electricity exists and differs, and differs to be pi/2, induction current has been subdued driving lamp tube current intensity, thereby the luminescence efficiency of fluorescent tube is reduced, also can cause fluorescent tube high-pressure side and low pressure end luminance difference apart from excessive because of the electric current difference of fluorescent tube diverse location.

Summary of the invention

The purpose of this utility model provides a kind of side-light type module backlight, solves because of stray capacitance between reflex housing and the fluorescent tube produces induced current, cause the luminescence efficiency of fluorescent tube to reduce and the luminance difference of fluorescent tube high-pressure side and low pressure end apart from problems of too.

For achieving the above object, side-light type of the present utility model module backlight comprises: light guide plate; Two groups of cold cathode fluorescent lamp are positioned over the both sides of described light guide plate respectively; Two fluorescent tube reflex housings are positioned over respectively around two groups of cold cathode fluorescent lamp, and each reflex housing comprises reflex housing bottom surface, reflex housing side and three faces of reflex housing end face, and described cold cathode fluorescent lamp three bread are enclosed; Reflector plate is positioned over the below of described light guide plate; Backboard is positioned over the below of described reflector plate, and the side of described backboard and bottom surface form lamp box jointly; There is bottom recesses, lateral grooves and the end face groove that the direction that deviates to cold cathode fluorescent lamp respectively outwards is bent to form the position corresponding with described cold cathode fluorescent lamp on described reflex housing bottom surface, reflex housing side and the reflex housing end face.

The cross sectional shape of described bottom recesses, lateral grooves and end face groove is a rectangle, and is perhaps trapezoidal, perhaps arc.

The outside of described bottom recesses and lateral grooves contacts with described backboard.

Side-light type of the present utility model module backlight has effectively reduced the induction current that produces owing to stray capacitance between reflex housing and the fluorescent tube, has guaranteed the luminescence efficiency and the luminous homogeneity of lamp tube ends of fluorescent tube.

Description of drawings

Fig. 1 is the schematic cross-section of existing side-light type module backlight;

Fig. 2 is the schematic cross-section of side-light type of the present utility model module backlight;

Fig. 3 is the local enlarged diagram of A part of side-light type module backlight among Fig. 2;

Fig. 4 is the schematic perspective view of an embodiment of reflex housing.

Embodiment

The stray capacitance that produces between reflex housing 14 shown in Fig. 1 and the fluorescent tube 13 is equivalent to capacity plate antenna, capacity plate antenna formula C=ε s/4 π kd, and wherein ε is a specific inductive capacity; S is dull and stereotyped over against area; K is that static is constant; π is a constant; D is the distance of parallel-plate.From formula, increase as can be seen d promptly increase between reflex housing 14 and the fluorescent tube 13 apart from the stray capacitance C1 that produces between them, C2, C3, thus can reduce the induction current of generation, prevention is low because of the lamp luminescence efficient that it produces, the problem of fluorescent tube luminance nonuniformity.For the distance that makes capacity plate antenna increases, need increasing fluorescent tube and reflex housing over against distance.

Below in conjunction with accompanying drawing inventive embodiment is further described:

Fig. 2 is the schematic cross-section of side-light type of the present utility model module backlight, and Fig. 3 is the local enlarged diagram of A part of side-light type module backlight among Fig. 2, and as shown in the figure, side-light type of the present utility model module backlight comprises: several blooming pieces 100; One light guide plate 200 is positioned over the below of blooming piece 100; Two groups of cold cathode fluorescent lamp 300 are positioned over the both sides of light guide plate 200 respectively; Two fluorescent tube reflex housings 400 are positioned over respectively around two groups of cold cathode fluorescent lamp 300; One reflector plate 500 is positioned over the below of light guide plate 200; One backboard 600 is positioned over the below of reflector plate 500, and the side of backboard 600 and bottom surface form lamp box jointly; One glue frame 700, be positioned over backboard 600 above, surround described lamp box.

For the distance that makes capacity plate antenna increases, need increasing cold cathode fluorescent lamp 300 and reflex housing 400 over against distance.Therefore, part corresponding with cold cathode fluorescent lamp 300 on the reflex housing 400 is bent to form groove to the direction opposite with fluorescent tube, can increases the capacity plate antenna distance of cold cathode fluorescent lamp 300 and reflex housing 400 like this.As shown in Figure 3, reflex housing 400 is divided into three parts, a part is reflex housing bottom surface 410, a part is reflex housing side 420, another part is a reflex housing end face 430, cold cathode fluorescent lamp 300 3 bread are enclosed in the combination of three parts, and the light that cold cathode fluorescent lamp 300 is sent can only be propagated to light guide plate 200 directions.Reflex housing bottom surface 410, reflex housing side 420 and reflex housing end face 430 outwards are bent to form bottom recesses 411, lateral grooves 421 and end face groove 431 to the direction that deviates from cold cathode fluorescent lamp 300 respectively.The depth d 3 of the depth d 1 of bottom recesses 411, the depth d 2 of lateral grooves 421 and end face groove 431 can be the same or different, and decides according to the size of the module backlight of specific design.The outside of bottom recesses 411 and lateral grooves 421 contacts with backboard 600, can guarantee reflex housing 400 abundant ground connection.

Backboard 600 can be done corresponding grooves (not drawing among the figure) on the position with respect to the bottom recesses 411 of reflex housing 400 and lateral grooves 421, such design, on the basis that does not increase side-light type module physical dimension backlight, increase cold cathode fluorescent lamp 300 and reflex housing 400 over against distance, thereby reduced leakage current.

The cross sectional shape of bottom recesses 411, lateral grooves 421 and end face groove 431 can be rectangle, and is trapezoidal, or other shapes such as arc.

Bottom recesses 411, lateral grooves 421 and end face groove 431 can be linear pattern or shaped form along the distribution of the length direction of cold cathode fluorescent lamp 300, can be continuous long recess, also can be discontinuous a plurality of grooves.The schematic perspective view of an embodiment of the reflex housing 400 after the bending there is shown the linear discontinuous a plurality of grooves that distribute along cold cathode fluorescent lamp 300 directions as shown in Figure 4.

The foregoing description only is used to illustrate the utility model; those skilled in the art can make various modifications or replacement to embodiment of the present utility model; and not departing from spirit of the present utility model, these modifications or replacement should be considered as dropping in the protection domain of the present utility model.

Claims

1, a kind of side-light type module backlight comprises:

Light guide plate;

Two groups of cold cathode fluorescent lamp are positioned over the both sides of described light guide plate respectively;

Two fluorescent tube reflex housings are positioned over respectively around two groups of cold cathode fluorescent lamp, and each reflex housing comprises reflex housing bottom surface, reflex housing side and three faces of reflex housing end face, with described

Cold cathode fluorescent lamp three bread enclose;

Reflector plate is positioned over the below of described light guide plate;

Backboard is positioned over the below of described reflector plate, and the side of described backboard and bottom surface form lamp box jointly;

It is characterized in that there is bottom recesses, lateral grooves and the end face groove that the direction that deviates to cold cathode fluorescent lamp respectively outwards is bent to form the position corresponding with described cold cathode fluorescent lamp on described reflex housing bottom surface, reflex housing side and the reflex housing end face.

2, side-light type as claimed in claim 1 module backlight is characterized in that, the cross sectional shape of described bottom recesses, lateral grooves and end face groove is a rectangle, and is perhaps trapezoidal, perhaps arc.

3, side-light type as claimed in claim 1 module backlight is characterized in that, the outside of described bottom recesses and lateral grooves contacts with described backboard.