KR20090062423A - Surface light source device and backlight unit having the same - Google Patents

Surface light source device and backlight unit having the same Download PDF

Info

Publication number
KR20090062423A
KR20090062423A KR1020070129662A KR20070129662A KR20090062423A KR 20090062423 A KR20090062423 A KR 20090062423A KR 1020070129662 A KR1020070129662 A KR 1020070129662A KR 20070129662 A KR20070129662 A KR 20070129662A KR 20090062423 A KR20090062423 A KR 20090062423A
Authority
KR
South Korea
Prior art keywords
electrode
light source
voltage
source device
discharge
Prior art date
Application number
KR1020070129662A
Other languages
Korean (ko)
Inventor
강동곤
김길호
이선호
홍재선
Original Assignee
삼성코닝 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 삼성코닝 주식회사 filed Critical 삼성코닝 주식회사
Priority to KR1020070129662A priority Critical patent/KR20090062423A/en
Publication of KR20090062423A publication Critical patent/KR20090062423A/en

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133604—Direct backlight with lamps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/06—Main electrodes
    • H01J61/067—Main electrodes for low-pressure discharge lamps
    • H01J61/0672—Main electrodes for low-pressure discharge lamps characterised by the construction of the electrode
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/30—Vessels; Containers
    • H01J61/305—Flat vessels or containers

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Planar Illumination Modules (AREA)
  • Liquid Crystal (AREA)

Abstract

The present invention includes a light source body having a discharge space into which a discharge gas is injected, a first voltage electrode applying a first voltage to the discharge space, and a second voltage electrode applying a second voltage. The first voltage electrode and the second voltage electrode are arranged to be spaced apart from each other to form a main electrode, and is arranged between the main electrodes to provide a surface light source device, characterized in that. In example embodiments, the main electrode is formed on a first surface of the light source body, and the auxiliary electrode is formed on a second surface of the light source body opposite to the first surface. The first surface may be a light exit surface from which light is emitted to the outside. According to one embodiment, the main electrode is the first voltage electrode and the second voltage electrode are arranged alternately. According to one embodiment, at least one of the first voltage electrode and the second voltage electrode of the main electrode is made of a pair of sub-electrodes. According to one embodiment, adjacent main and auxiliary electrodes are arranged such that the same voltage electrode is provided. According to one embodiment, the light source body has a plurality of discharge spaces. The main electrode and the auxiliary electrode may be formed to cross the length direction of the plurality of discharge spaces. According to one embodiment, the width of the main electrode is smaller than the width of the auxiliary electrode. The width of the main electrode may be 1.5 ~ 2.5mm, the width of the auxiliary electrode may be 4.5 ~ 5.5mm. According to one embodiment, the separation distance between the main electrode is 28 ~ 32mm, the separation distance between the auxiliary electrode is 8 ~ 12mm.

Description

Surface light source device and backlight unit having the same {SURFACE LIGHT SOURCE DEVICE AND BACKLIGHT UNIT HAVING THE SAME}

The present invention relates to a surface light source device and a backlight unit having the same, and more particularly, to a surface light source device having excellent discharge efficiency and having a low discharge start voltage and a backlight unit having the same.

The liquid crystal display displays an image by using electrical and optical characteristics of the liquid crystal. Since the liquid crystal part of the liquid crystal display is a light receiving element that does not generate light by itself, it separately requires a rear light source, that is, a backlight.

Light supplied from the rear light source sequentially passes through the pixel electrode, the liquid crystal, and the common electrode of the liquid crystal display. In this case, the display quality of the image passing through the liquid crystal largely depends on the luminance and luminance uniformity of the rear light source. In general, the higher the luminance and the uniformity of the luminance, the better the display quality.

BACKGROUND ART In the back light source of a conventional liquid crystal display device, a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED) is mainly used.

Cold cathode fluorescent lamps have the advantage of high brightness, long life, and very low heat generation compared to incandescent lamps. On the other hand, the light emitting diode has a high power consumption, but has an advantage of excellent brightness. However, cold cathode fluorescent lamps or light emitting diodes have poor luminance uniformity. Therefore, existing back light sources require optical members such as a light guide panel (LGP), a diffusion member, a prism sheet, and the like to increase luminance uniformity. As a result, the liquid crystal display has a problem in that the volume and weight of the optical member are greatly increased.

Therefore, a flat fluorescent lamp (FFL) in the form of a flat plate has been proposed.

The conventional surface light source device comprises a light source body and an electrode.

The light source body has a discharge space in which discharge gas is injected. The light source body includes a first substrate and a second substrate. The first substrate and the second substrate are sealed at edges to have a discharge space between the first substrate and the second substrate.

The electrode applies a discharge voltage to the discharge gas. When a discharge voltage is applied to the discharge gas, visible light is generated, and the generated visible light is emitted through the substrate.

However, the conventional surface light source device has a problem of poor discharge efficiency. It is possible to increase the discharge efficiency by increasing the separation distance between the electrodes, but this is because the discharge start voltage is high, there is a limit.

Therefore, there is an urgent need for a surface light source device having excellent discharge efficiency and low discharge voltage.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a surface light source device having a low discharge start voltage while having excellent discharge efficiency and a backlight unit having the same.

In order to achieve the above object, the present invention provides a light source body having a discharge space in which a discharge gas is injected, a first voltage electrode for applying a first voltage to the discharge space, and a second for applying a second voltage. A surface light source device comprising a voltage electrode, wherein the first voltage electrode and the second voltage electrode are spaced apart from each other to form a main electrode, and are arranged between the main electrodes to form an auxiliary electrode. To provide.

In example embodiments, the main electrode is formed on a first surface of the light source body, and the auxiliary electrode is formed on a second surface of the light source body opposite to the first surface. The first surface may be a light exit surface from which light is emitted to the outside.

According to one embodiment, the main electrode is the first voltage electrode and the second voltage electrode are arranged alternately.

According to one embodiment, at least one of the first voltage electrode and the second voltage electrode of the main electrode is made of a pair of sub-electrodes.

According to one embodiment, the adjacent main electrode and the auxiliary electrode are arranged so that the same voltage electrode.

According to one embodiment, the light source body has a plurality of discharge spaces. The main electrode and the auxiliary electrode may be formed to cross the length direction of the plurality of discharge spaces.

According to one embodiment, the width of the main electrode is smaller than the width of the auxiliary electrode. The width of the main electrode may be 1.5 ~ 2.5mm, the width of the auxiliary electrode may be 4.5 ~ 5.5mm.

According to one embodiment, the separation distance between the main electrode is 28 ~ 32mm, the separation distance between the auxiliary electrode is 8 ~ 12mm.

The present invention also provides a backlight unit for supplying a first voltage and a second voltage to the surface light source device and the first voltage electrode and the second voltage electrode of the surface light source device, respectively.

According to the above configuration, the present invention can provide a surface light source device having a low discharge start voltage while having excellent discharge efficiency and a backlight unit having the same.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing a surface light source device according to a first embodiment of the present invention, Figure 2 is a cross-sectional view taken along the line II-II of the surface light source device of FIG.

The surface light source device of FIG. 1 includes a light source body 110 and electrodes 171 and 172.

The light source body 110 includes a first substrate 120 and a second substrate 130. The first substrate 120 and the second substrate 130 are preferably transparent flat glass substrates.

The first substrate 120 and the second substrate 130 are opposed to each other at predetermined intervals, and the sealing member 140 is interposed between the first substrate 120 and the second substrate 130 to form a sealed discharge space 160 therein. According to the exemplary embodiment, the sealed discharge space 160 may be formed by directly bonding or fusing the edges of the first substrate 120 and the second substrate 130 without interposing the sealing member 140. .

A fluorescent layer (not shown) is applied to the inner surface of the first substrate 120 (or the second substrate 130), and a reflective layer is disposed on the inner surface of the second substrate 130 (or the first substrate 120) facing the substrate. (Not shown) is formed, and a fluorescent layer (not shown) is formed on the reflective layer.

The spacer (not shown) is interposed in the discharge space 160 to maintain the gap of the discharge space 160. The spacer may be bonded to or integrally formed with the first substrate 120 and the second substrate 130. For example, an embodiment in which the spacer is formed integrally with the first substrate 120 by molding the first substrate 120 may be possible.

The spacer is preferably made of a material that is transparent to visible light.

The spacer is in island form. Therefore, the interior defined by the first substrate 120 and the second substrate 130 forms a single discharge space 160 having one open structure. The distance between the first substrate 120 and the second substrate 130 is very small compared to the substrate area, and is formed in a single space, so that the vacuum exhaust and discharge gas are easily injected.

Discharge gas is injected into the discharge space 160 of the light source body 110.

As the discharge gas, various kinds of discharge gas may be selected, but preferably, a gas excluding mercury such as xenon, argon, neon, other inert gas, or a mixture thereof is used.

In particular, when a discharge gas excluding mercury is used, it not only provides an environmentally friendly advantage, but also shortens the luminance stabilization time even when driving at low temperature. In addition, due to the temperature sensitivity of the mercury, it provides an advantage that can minimize the problem that the brightness uniformity of the surface light source device in accordance with the temperature deviation.

The electrode includes a first voltage electrode and a second voltage electrode.

The first voltage electrode applies a first voltage to the discharge gas, and the second voltage electrode applies a second voltage to the discharge gas. When a discharge voltage is applied to the discharge gas, ultraviolet rays are generated by the discharge of the discharge gas. The generated ultraviolet rays excite the fluorescent layer to generate visible light, and the generated visible light is transmitted forward through the substrate.

At least, the electrode formed on the emission-side substrate of visible light preferably has an open ratio of 60% or more to expose the substrate in order to increase the transmittance of light emitted by the discharge from the light source body 110.

The electrode may use a transparent electrode (eg, ITO), other conductive materials may be used, and preferred materials include copper, silver, gold, aluminum, nickel, chromium, ITO, carbon-based conductive materials, conductive polymers, or the like. Any one material selected from composite materials may be used.

The electrodes may be formed by directly printing the patterns of the individual electrodes on the surface of the light source body 110. Alternatively, the electrodes may be attached to a film of insulating material to form a multilayer film, and then the multilayer film may be formed. It may be attached to the surface of the light source body (110).

The first substrate 120 and the second voltage electrode are arranged at a distance from each other to form a main electrode 171 on the first substrate 120. In the second substrate 130, a first voltage electrode and a second voltage electrode are arranged between the main electrode 171 to form the auxiliary electrode 172.

1 illustrates an embodiment in which the main electrode 171 and the auxiliary electrode 172 are formed on different substrates, but are not necessarily limited thereto.

In addition, FIG. 1 illustrates an exemplary embodiment in which the main electrode 171 is formed on the first substrate 120 which is the light emitting surface and is formed on the second substrate 130 which is the auxiliary electrode 172. However, the present invention is not limited thereto.

In the main electrode 171, the first voltage electrode and the second voltage electrode are alternately arranged.

Adjacent main electrode 171 and auxiliary electrode 172 are arranged such that the same voltage electrode comes. That is, if the main electrode 171 is the first voltage electrode, the auxiliary electrode 172 adjacent to the main electrode 171 is also arranged so that the first voltage electrode comes.

Preferably, the width of the main electrode 171 is smaller than the width of the auxiliary electrode 172 to cover as little light as possible. More preferably, the width of the main electrode 171 is 1.5 ~ 2.5mm, the width of the auxiliary electrode 172 is 4.5mm ~ 5.5mm. More preferably, the width of the main electrode 171 is 2 mm, and the width of the auxiliary electrode 172 is 5 mm.

Preferably, the separation distance between the main electrodes 171 is 28 to 32 mm, and the separation distance between the auxiliary electrodes 172 is 8 to 12 mm. More preferably, the separation distance between the main electrodes 171 is 30 mm, and the separation distance between the auxiliary electrodes 172 is 10 mm.

As described above, in the conventional surface light source device, the discharge interval, that is, the separation distance between the first voltage electrode and the second voltage electrode, is extremely limited. When the interval is widened, it is possible to sufficiently use the positive liquor and improve the discharge efficiency. However, due to the high discharge start voltage, it is limited to widen the discharge interval. In particular, in the case of the surface light source device of, for example, Xe discharge gas in which mercury was removed as the discharge gas, it was almost impossible to widen the discharge interval.

Accordingly, in the present invention, as shown in FIG. 1, the auxiliary electrode 172 having the same polarity is disposed inside the main electrode 171 to lower the starting voltage and improve the discharge efficiency.

Such an electrode structure can drastically reduce discharge condensation that can occur in a wide discharge interval, thereby inducing stable discharge.

Looking at the discharge mechanism, when a discharge voltage is applied, a discharge occurs first between the auxiliary electrode 172 at a low voltage (for example, 2.5 kV), and the discharge spreads to the main electrode 171 by the plasma formed and is stable. A discharge is formed.

The device having the above discharge structure showed high efficiency (for example, 8 cd / W) with low starting voltage characteristics.

3 is a cross-sectional view showing a surface light source device according to a second embodiment of the present invention.

At least one of the first voltage electrode and the second voltage electrode of the main electrode 171 may be formed of a pair of sub electrodes. 3 illustrates an embodiment in which both the first voltage electrode and the second voltage electrode are formed of sub-electrode pairs. By such a configuration, it is possible to reduce discharge interference between adjacent discharges.

4 is a perspective view illustrating a surface light source device according to a third embodiment of the present invention, FIG. 5 is a cross-sectional view taken along line VV of the surface light source device of FIG. 4, and FIG. 6 is a light output of the surface light source device of FIG. 4. The figure shows the state.

As shown, the surface light source device of this embodiment has a plurality of discharge spaces 160 therein.

In the illustrated embodiment, an embodiment in which the partition wall 121 divided into the plurality of discharge spaces 160 is integrally formed on the first substrate 120 is illustrated, but is not necessarily limited thereto.

In some embodiments, the partition wall may be integrally formed on the second substrate 130, or the partition wall may be integrally formed on both the first substrate 120 and the second substrate 130. In addition, the partition wall may be interposed between the first substrate 120 and the second substrate 130 independently of the first substrate 120 and the second substrate 130.

In the present embodiment, the plurality of discharge spaces 160 are partitioned to form independent spaces, but according to the embodiment, the plurality of discharge spaces 160 may be connected to each other to have a serpentine shape.

The discharge space 160 may have various cross-sectional shapes such as trapezoidal, semicircular, circular, semi-elliptic, and elliptical.

In FIG. 4, an embodiment in which the main electrode 171 and the discharge electrode are formed to cross the longitudinal direction of the discharge space 160 is illustrated, but is not necessarily limited thereto.

7 is an exploded perspective view showing a backlight unit according to a fourth embodiment of the present invention.

As illustrated, the backlight unit includes a bottom chassis 200, an optical member 500, a fixed frame 600, and an inverter 700 in addition to the surface light source device 100.

The bottom chassis 200 accommodates the surface light source device 100.

The surface light source device 100 employs the surface light source device of FIG. 4 for illustrative purposes, but the surface light source device of various other structures may be used.

The optical member 500 may include a diffusion plate and a prism sheet. The diffusion plate diffuses the light emitted from the surface light source device 100 to increase the luminance uniformity. The prism sheet imparts straightness to the light diffused by the diffuser plate to increase the front luminance.

The fixed frame 600 is coupled to the bottom chassis 200 to fix the optical member 500. In the LCD, the liquid crystal panel is positioned in front of the fixed frame 600.

The inverter 700 drives the surface light source device 100 by generating a high potential discharge voltage and supplying the discharge voltage to the electrode.

1 is a perspective view showing a surface light source device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line II-II of the surface light source device of FIG. 1.

3 is a cross-sectional view showing a surface light source device according to a second embodiment of the present invention.

4 is a perspective view showing a surface light source device according to a third embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along line V-V of the surface light source device of FIG. 4.

6 is a view illustrating a light exit state of the surface light source device of FIG. 4.

7 is a perspective view illustrating a backlight unit according to a fourth embodiment of the present invention.

Claims (12)

A light source body having a discharge space into which discharge gas is injected; It includes a first voltage electrode for applying a first voltage to the discharge space and a second voltage electrode for applying a second voltage, And the first voltage electrode and the second voltage electrode are spaced apart from each other to form a main electrode, and are arranged between the main electrodes to form an auxiliary electrode. The method of claim 1, The main electrode is formed on the first surface of the light source body, The auxiliary electrode is a surface light source device, characterized in that formed on the second surface of the light source body facing the first surface. The method of claim 2, The first surface is a surface light source device, characterized in that the light exit surface is emitted to the outside. The method of claim 1, The main electrode is a surface light source device, characterized in that the first voltage electrode and the second voltage electrode are alternately arranged. The method of claim 1, And at least one of the first voltage electrode and the second voltage electrode of the main electrode comprises a sub-electrode pair. The method of claim 1, Adjacent main electrodes and auxiliary electrodes are surface light source device characterized in that the same voltage electrode is arranged to come. The method of claim 1, The light source body has a surface light source device characterized in that it comprises a plurality of discharge spaces. The method of claim 7, wherein And the main electrode and the auxiliary electrode are formed to cross the length direction of the plurality of discharge spaces. The method of claim 1, The width of the main electrode is a surface light source device, characterized in that less than the width of the auxiliary electrode. The method of claim 9, The width of the main electrode is 1.5 ~ 2.5mm, the width of the auxiliary electrode is a surface light source device, characterized in that the 4.5 ~ 5.5mm. The method of claim 1, The distance between the main electrode is 28 ~ 32mm, the distance between the auxiliary electrode is a surface light source device, characterized in that 8 ~ 12mm. The surface light source device of any one of claims 1 to 11, And a backlight unit for supplying a first voltage and a second voltage to the first voltage electrode and the second voltage electrode of the surface light source device, respectively.
KR1020070129662A 2007-12-13 2007-12-13 Surface light source device and backlight unit having the same KR20090062423A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020070129662A KR20090062423A (en) 2007-12-13 2007-12-13 Surface light source device and backlight unit having the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020070129662A KR20090062423A (en) 2007-12-13 2007-12-13 Surface light source device and backlight unit having the same

Publications (1)

Publication Number Publication Date
KR20090062423A true KR20090062423A (en) 2009-06-17

Family

ID=40991673

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020070129662A KR20090062423A (en) 2007-12-13 2007-12-13 Surface light source device and backlight unit having the same

Country Status (1)

Country Link
KR (1) KR20090062423A (en)

Similar Documents

Publication Publication Date Title
KR100710430B1 (en) Surface light source device and back light unit having the same
JP2005347262A (en) Planer light source device, and backlight unit equipped with the same
KR20090062423A (en) Surface light source device and backlight unit having the same
KR20090025521A (en) Electrode material and method for preparing the same and and backlight unit having the same
KR20080053769A (en) Surface light source and backlight unit having the same
KR20090072182A (en) Surface light source and backlight unit having the same
KR20090061280A (en) Surface light source and backlight unit having the same
KR20060120768A (en) Surface light source device and back light unit having the same
KR20090048783A (en) Surface light source and backlight unit having the same
KR20090078154A (en) Surface light source and driving device for lamp and backlight unit having the same
KR20090078155A (en) Tube type lamp and backlight unit having the same
KR20090067755A (en) Surface light source and backlight unit having the same
KR20090051841A (en) Surface light source and backlight unit having the same
KR20090055849A (en) Surface light source and backlight unit having the same
KR20090081822A (en) Device for driving surface light source device and surface light source device and backlight unit using the same
KR20090062424A (en) Surface light source and backlight unit having the same
KR20090070312A (en) Surface light source and backlight unit having the same
KR20060023655A (en) Surface light source device and back light unit having the same
KR20090056119A (en) Surface light source and backlight unit having the same
KR20090077472A (en) Surface light source and backlight unit having the same
KR20080068947A (en) Surface light source with electrode cells, and backlight unit having the same
KR20090086720A (en) Surface light source and backlight unit having the same
KR20090067754A (en) Surface light source and backlight unit having the same
KR20090062425A (en) Surface light source and backlight unit having the same
KR20090067758A (en) Surface light source and backlight unit having the same

Legal Events

Date Code Title Description
WITN Withdrawal due to no request for examination