KR20080032527A - Apparatus for forming spacer, surface light source and backlight unit having the same - Google Patents

Abstract

An apparatus for forming a spacer of a surface light source, a surface light source apparatus and a backlight unit having the same are provided to help arrangement of spacers and attach the plural spacers through once process by using a jig plate and a compressing member having a simple structure, thereby significantly improving mass productivity. An apparatus for forming a spacer of a surface light source comprises the following parts. A jig plate(300) is a structure of a plate shape, and includes plural through-holes spaced from each other at predetermined intervals. A compressing member(320) is a structure of a plate shape, and includes plural protrusion units(325) formed in locations corresponding to the through-holes. The surface light source comprises the following parts. First and second flat substrates(210,220) form an airtight discharge space. Plural spacers(235) maintain the discharge space at predetermined intervals.

Description

Spacer forming apparatus of a surface light source device, a surface light source device and a backlight unit having the same {APPARATUS FOR FORMING SPACER, SURFACE LIGHT SOURCE AND BACKLIGHT UNIT HAVING THE SAME}

1 is a perspective view showing an example of a surface light source device.

2 is a perspective view showing a surface light source device according to the present invention.

Figure 3 is a side view showing a surface light source device according to the present invention.

4 is a sectional view taken along the line X-X 'of FIG.

5 is an enlarged view of a portion A of FIG. 4;

Figure 6 is a cross-sectional view showing an electrode portion of a multi-layer structure according to the present invention.

7 is a flowchart illustrating a spacer forming process of the surface light source device of the present invention.

8 to 10 are perspective views illustrating a process of attaching a spacer to a substrate.

Figure 11 is a perspective view showing a jig plate for spacer formation of the present invention.

12 to 14 are cross-sectional views showing a process of forming a spacer using a jig plate.

15 is an exploded perspective view showing a backlight unit including the surface light source device of the present invention.

*** Explanation of symbols for the main parts of the drawing ***

200: surface light source device 210: first substrate

220: second substrate 230: sealing member

235: spacer 240: discharge space

250: first surface electrode part 260: second surface electrode part

300: jig plate 320: crimping member

The present invention relates to an ultra-thin surface light source device, a manufacturing method thereof, and a backlight unit having the same, and particularly provides a new surface light source device suitable for a mercury-free lamp.

The liquid crystal display displays an image by using electrical and optical characteristics of the liquid crystal. Liquid crystal displays have the advantages of being very small in volume and light in weight compared to cathode ray tubes (CRTs). As a result, they are widely used in portable computers, communication devices, liquid crystal television receivers, and aerospace industries. .

The liquid crystal display device includes a liquid crystal controller for controlling liquid crystal and a rear light source for supplying light to the liquid crystal. The liquid crystal controller includes a pixel electrode disposed on the first substrate, a common electrode disposed on the second substrate, and a liquid crystal interposed between the pixel electrode and the common electrode. The pixel electrode is formed in plural in correspondence with the resolution, and the common electrode is made of one and facing the pixel electrode. A thin film transistor (TFT) is connected to each pixel electrode to apply a pixel voltage having a different level, and a reference voltage of the same level is applied to the common electrode. The pixel electrode and the common electrode are made of a transparent material having conductivity.

Light supplied from the rear light source sequentially passes through the pixel electrode, the liquid crystal, and the common electrode. 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.

Conventionally, the rear light source of the liquid crystal display is mainly used a cold cathode fluorescent lamp (CCFL) having a rod shape or a light emitting diode (LED) having a dot shape. Cold cathode ray tube lamp has 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 ray tube type lamps or light emitting diodes have poor brightness uniformity. Accordingly, a rear light source having a cold cathode ray tube lamp or a light emitting diode as a light source is an optical member such as a light guide panel (LGP), a diffusion member, a prism sheet, or the like to increase luminance uniformity. (optical member) is required. As a result, a liquid crystal display using a cold cathode ray tube lamp or a light emitting diode has a problem in that the volume and weight of the optical member are greatly increased.

As a back light source for a liquid crystal display, a flat fluorescent lamp (FFL) in the form of a flat plate has been proposed. Referring to FIG. 1, the conventional surface light source device 100 includes a light source body 110 and electrodes 160 provided on outer surfaces of both edges of the light source body 110. The light source body 110 includes first and second substrates disposed to face each other at predetermined intervals. A plurality of partitions 140 are disposed between the first and second substrates to partition the space between the first and second substrates into a plurality of discharge channels 120. A sealing member (not shown) is disposed between the edges of the first and second substrates to isolate the discharge channels 120 from the outside. Discharge gas is injected into the discharge space 150 inside the discharge channel.

In order to discharge-drive the surface light source device, an electrode is applied to the first substrate and the second substrate or one of the two substrates so that the electrodes have the same area per discharge channel in the form of a strip of strips or in the form of island electrodes. Therefore, when the surface light source device is driven using an inverter, all the front channels are discharged in the same manner.

The surface light source device has a problem in that luminance uniformity is not good because the light emission characteristics vary depending on the position of the discharge channel. In addition, there is a problem that a dark portion is generated by channeling due to interference between adjacent channels between a plurality of discharge channels.

In particular, the existing surface light source device contains mercury (Hg) as a discharge gas, which is not only environmentally problematic, but also increases the luminance stabilization time when driving at low temperatures, and the temperature variation of the surface light source itself due to the temperature sensitivity of mercury. As a result, there is a problem in that the luminance uniformity is lowered. In addition, many solutions remain for the enlargement of the surface light source device.

It is an object of the present invention to provide a novel surface light source device suitable for large area.

Another object of the present invention is to provide a surface light source device and a backlight unit which are excellent in brightness and luminance uniformity and which are thin.

Still another object of the present invention is to provide a surface light source device suitable for a discharge gas excluding mercury.

It is still another object of the present invention to provide a surface light source device having a novel structure suitable for mass production and its manufacturing equipment.

Other objects and features of the present invention will be presented in more detail below.

The present invention relates to a surface light source device including a jig plate including a plurality of holes spaced at predetermined intervals as a plate-shaped structure, and a pressing member having a plurality of protrusions formed at positions corresponding to the holes as a plate-shaped structure. Provided is a spacer forming apparatus.

Preferably, the upper end of the through hole of the jig plate is formed to have a width wider than an inner diameter. In addition, the protrusion of the crimping member is preferably smaller in diameter than the through hole of the jig plate.

The present invention also includes a plate-type first substrate and a plate-type second substrate forming a sealed discharge space, and a plurality of spacers for maintaining the discharge space at predetermined intervals, wherein the plurality of spacers are spaced at predetermined intervals. The present invention provides a surface light source device and a backlight unit including the same, wherein the surface light source device has a strength to withstand a vacuum of 10 ⁻⁷ torr as a high temperature frit or a ceramic material.

In the surface light source device and the backlight unit of the present invention, a plurality of spacers are formed at predetermined intervals by using the spacer forming device. In addition, since a plurality of spacers can be attached in one step, mass production is excellent, and it is particularly easy to form a spacer in a large-area surface light source device.

The surface light source device and the backlight unit according to the present invention can have an ultra-thin structure of extremely thin overall thickness. The enclosed space formed by the first substrate, the second substrate, and the spacer forms an internal discharge space having an open structure, and an eco-friendly product may use a gas excluding mercury as a discharge gas injected into the discharge space. Applicable to In addition, since the discharge space is not partitioned by the partition wall, the luminance and luminance uniformity of the light emitted to the entire surface of the substrate are excellent.

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

2 is a perspective view showing the surface light source device 200 according to an embodiment of the present invention, Figure 3 is a side view.

The surface light source device 200 includes a planar first substrate 210 and a planar second substrate 220 having the same shape. The first substrate 210 and the second substrate 220 is preferably a transparent thin glass substrate, each thickness is not particularly limited, but a thickness of about 1 ~ 2 mm, preferably 1 mm or less is suitable.

A fluorescent layer may be coated on the inner surfaces of the first substrate 210 and the second substrate 220, and a reflective film may be further formed on one of the first substrate and the second substrate. The first substrate 210 and the second substrate 220 face each other at predetermined intervals, and a sealing member 230 such as a frit is inserted into an edge thereof to form a sealed space. Alternatively, the first substrate and the second substrate may be directly bonded using, for example, a heating means such as a laser to form a closed space.

In the surface light source device according to the present invention, a large area flat plate electrode is formed on an outer surface of a light source body formed by a first substrate and a second substrate. FIG. 4 is a cross-sectional view taken along line X-X 'of FIG. 2, and FIG. 5 is an enlarged view of portion A of FIG. 4, and as illustrated, the outer surfaces of the first and second substrates 210 and 220 are respectively formed. The first surface electrode portion 250 and the second surface electrode portion 260 are formed. The first surface electrode part 250 and the second surface electrode part 260 are formed of a surface electrode having a flat plate shape substantially covering the entire substrate area.

At least one of the first surface electrode portion 250 and the second surface electrode portion 260 preferably has an open ratio of 60% or more to expose the substrate to increase the transmittance of light emitted by the discharge from the light source body. Do.

In the surface light source device according to the present invention, the first surface electrode portion 250 and the second surface electrode portion 260 may use a transparent electrode (eg, ITO), and may use an electrode having a predetermined pattern. have. FIG. 6 is a cross-sectional view of an electrode unit according to an exemplary embodiment of the present invention. As illustrated, the lower base layer 252, the electrode pattern 256 formed on the base layer, and the base layer and the electrode pattern are disposed on the electrode layer 256. The electrode part of the multilayered structure of the protective layer 254 formed in can be confirmed. The base layer and the protective layer are preferably transparent to visible light.

In the case of an electrode part including only an electrode pattern, bonding to a glass substrate may be difficult and durability may be degraded, whereas the electrode part of the multilayer structure may be easily bonded to a substrate and ensure durability of the electrode pattern, and various types of electrode patterns may be used. There is an advantage that can be formed.

The base layer 252 uses a transparent polymer material as a material resistant to thermal shock, and the electrode pattern 256 is a material having excellent conductivity of copper, silver, gold, aluminum, nickel, chromium, carbon, or polymer. It is possible to use a material in which the material is compounded. The protective layer 254 uses a transparent polymer material resistant to thermal shock.

The electrode pattern of the plate type electrode portion used in the surface light source device of the present invention may be applied in various forms. For example, a pattern of a mesh structure, a stripe pattern, and other regular patterns of circles, ellipses, and polygons are possible. Discharge characteristics of the surface light source device are varied by different electrode pattern shapes of the first surface electrode portion 250 and the second surface electrode portion 260 formed on the first substrate 210 and the second substrate 220, respectively. It can change.

The first substrate 210 and the second substrate 220 are flat, and the interior defined by the first substrate, the second substrate, and the sealing member is divided by partition walls as in the conventional surface light source device. Instead of the discharge space, the discharge space 240 of one open structure is formed. The spacing between the first substrate and the second substrate is very small compared to the substrate area, and the internal space is formed in one open structure, so that the vacuum exhaust and discharge gas can be easily injected. In addition, it is suitable to construct a surface light source device using a gas other than mercury, for example, xenon, argon, neon, other inert gas, or a mixed gas thereof, as a discharge gas.

The vertical space of the discharge space 240 between the first substrate 210 and the second substrate 220 may be determined by the spacer 235. The number and spacing of the spacers 235 may be determined in a range that does not impair the luminance characteristics of the light emitted from the surface light source device. Alternatively, the height of the discharge space 240 may be defined by protrusions (not shown) integrally formed on the inner surface of the first substrate or the second substrate.

The spacer acts as a physical support means for external pressure when evacuating the closed discharge space formed by the substrate. Therefore, the spacer must have a high mechanical strength, and preferably a high temperature frit or ceramic material structure that can withstand an external pressure against a vacuum of 10 ⁻⁷ torr. In addition, when forming a plurality of spacers in the substrate, it is necessary to keep the spacing between the spacers constant.

In addition, a spacer process with good mass productivity needs to be developed to be suitable for mass production of surface light source devices.

7 is a flowchart illustrating a process of forming a spacer in the surface light source device according to the present invention. First, a flat substrate 210 or 220 is prepared (S1) (see FIG. 8), and a bonding means, for example, a frit 235 'is applied at a position where a spacer is to be formed on the substrate (S2) (FIG. 9). The frit applies the minimum amount necessary for bonding the spacers precisely at the formation position of the spacers. Various well known applicators may be used for the application of the frit.

Next, the spacers are aligned using the jig plate 300 in which a plurality of through holes 310 are formed as illustrated in FIG. 11 (S3). The jig plate performs an alignment process and a bonding process simultaneously so that a plurality of spacers can be simultaneously attached to the substrate. To this end, the jig plate is formed with a plurality of through holes 310 in the same position and spacing that the spacer is bonded to the substrate.

12, a plurality of spacers are respectively inserted into the through holes 310 of the jig plate 300. This process ensures that the spacers are aligned at appropriate intervals. The upper end 310 ′ of the through hole 310 is wider than the inside diameter of the through hole so that the spacer 235 can be easily inserted.

After the spacer 235 is inserted into each through hole 310 of the jig plate 300, the jig plate is adjusted to align with the spacer formation position on the substrate 210 or 220 as shown in FIG. 13.

When the alignment of the jig plate is completed, attach the spacer to the substrate (S4). A separate pressing member 320 may be moved from the top of the jig plate to the bottom to lower the spacer on the substrate surface (see FIG. 14). The pressing member 320 has a plurality of protrusions 325 formed at a position corresponding to the through hole 310 of the jig plate below the member surface on the plate. Therefore, a plurality of spacers inserted in the jig plate can be simultaneously lowered onto the substrate surface by a simple process of aligning the protrusion of the pressing member to the through hole and then moving the pressing member downward. The protrusion 325 of the pressing member is preferably smaller in diameter than the through hole 310 of the jig plate.

The plurality of spacers are bonded to the substrate surface as shown in FIG. 10 in an aligned state. Another planar substrate 220 or 210 is attached to the planar substrate on which the spacer is formed to complete the body of the surface light source device (S5).

As such, by using a jig plate and a pressing member having a simple structure in forming a plurality of spacers, spacer alignment may be easily performed, and a plurality of spacers may be attached in a single process, and thus mass productivity may be greatly improved. In addition, it is very easy to form a plurality of spacers in a large-area surface light source device.

15 is an exploded perspective view showing a backlight unit including the surface light source device according to the present invention. As shown, the backlight unit includes a surface light source 200, upper and lower cases 1100 and 1200, an optical sheet 900, and an inverter 1300. The lower case 1200 includes a bottom portion 1210 and a plurality of sidewall portions 1220 extending to form an accommodation space from an edge of the bottom portion 1210 to accommodate the surface light source 200. The surface light source 200 is accommodated in the storage space of the lower case 1200.

The inverter 1300 is disposed on the rear surface of the lower case 1200 and generates a discharge voltage for driving the surface light source 200. The discharge voltage generated from the inverter 1300 is applied to the electrode portion of the surface light source 200 through the first and second power lines 1352 and 1354, respectively. The optical sheet 900 may include a diffuser plate for uniformly diffusing the light emitted from the surface light source 200, a prism sheet for imparting linearity to the diffused light, and the like. The upper case 1100 is coupled to the lower case 1200 to support the surface light source 200 and the optical sheet 900. The upper case 1100 prevents the surface light source 200 from being separated from the lower case 1200.

Unlike the illustrated figure, the upper case 1100 and the lower case 1200 may be formed as one integrated case. On the other hand, the backlight unit according to the present invention may not include the optical sheet 900 because the brightness and luminance uniformity of the surface light source device is excellent.

Although described above with reference to preferred embodiments of the present invention, those skilled in the art or those skilled in the art without departing from the spirit and scope of the invention described in the claims to be described later Various modifications and variations can be made in the present invention without departing from the scope thereof.

According to the present invention, an ultra-thin surface area light source device and a backlight unit can be manufactured. In particular, spacer alignment is easy and a plurality of spacers can be attached in one step, thereby greatly improving mass productivity. The interior of the surface light source device including the spacer forms a discharge space having an open structure, and since the discharge space is not partitioned by the partition wall, the luminance and luminance uniformity of the light emitted to the front surface of the substrate are excellent.

Claims (10)

Jig plate comprising a plurality of holes spaced at predetermined intervals as a plate-shaped structure, A plate-shaped structure comprising a pressing member having a plurality of protrusions formed at a position corresponding to the through hole; Spacer forming apparatus of the surface light source device. The spacer forming apparatus of claim 1, wherein the upper end portion of the through hole of the jig plate is wider than an inner diameter. The spacer forming apparatus of claim 1, wherein the protrusion has a smaller diameter than the through hole. A planar first substrate and a planar second substrate forming a sealed discharge space; A plurality of spacers for maintaining the discharge space at a predetermined interval, The plurality of spacers are spaced at predetermined intervals, and have a strength to withstand a vacuum of 10 ^-7 torr as a high temperature frit or ceramic material Surface light source device. The surface light source device of claim 4, wherein the spacer is bonded to the first substrate or the second substrate via a frit. The surface light source device of claim 4, wherein the first substrate or the second substrate has an electrode formed on an outer surface thereof. The surface light source device of claim 6, wherein the electrode part comprises a base layer, an electrode pattern formed on an upper surface of the base layer, and a protective layer formed on the electrode pattern. The surface light source device according to claim 6, wherein the electrode portion has an aperture ratio of 60% or more for exposing the first substrate or the second substrate. The surface light source device of claim 4, wherein the first substrate and the second substrate form an internal discharge space having an open structure, and a discharge gas excluding mercury is injected into the discharge space. A planar first substrate and a planar second substrate forming a sealed discharge space, and a plurality of spacers for maintaining the discharge space at predetermined intervals, the plurality of spacers being spaced at a predetermined interval, A surface light source device having a strength to withstand a vacuum of 10 ^-7 torr as a high temperature frit or ceramic material, A case accommodating the surface light source device, and And an inverter configured to apply voltage to the first and second surface electrode parts. Backlight unit.

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