KR20060122463A - Surface light source device and backlight unit using the same - Google Patents

Abstract

A surface light source device and a backlight unit using the same are provided to reduce the consumption of mercury, thereby extending the lifetime of the surface light source device, by preventing the mercury from being absorbed in electrodes using auxiliary members. A surface light source device comprises a light source body(100) having a discharge part consisting of plural channels(140), and electrodes(130,130') provided at both ends of the light source body. One or more auxiliary members(200) are provided on a rear surface of the light source body across the plural channels. The auxiliary members irradiate the heat of the discharge part, thereby inducing the absorption of mercury in the discharge part. Each of the auxiliary members has a higher thermal conductivity than a glass constituting a rear substrate of the light source body.

Description

Surface light source device and backlight device using the same {SURFACE LIGHT SOURCE DEVICE AND BACKLIGHT UNIT USING THE SAME}

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

2 is a plan view of the surface light source device shown in FIG.

3 is a side view of the surface light source device shown in FIG. 1;

4 is an exploded perspective view showing the configuration of a backlight device using the surface light source device shown in FIG.

<Explanation of symbols for the main parts of the drawings>

100: light source body 200: auxiliary member

The present invention relates to a surface light source device and a backlight device using the same, and more particularly, to a surface light source device and a backlight device using the same, which can reduce the consumption of mercury and increase the lifespan.

Liquid crystal displays (LCDs) have a very small volume and light weight compared to cathode ray tubes (CRTs), and are widely used in portable computers, communication devices, liquid crystal television receivers, and aerospace industries. .

However, the liquid crystal display requires the use of a light source, that is, a backlight (BLU), for supplying light to a light receiving type (non-light emitting type).

Conventional backlights for LCDs have used cold cathode fluorescent lamps (CCFLs) in the form of customs and used them as light sources. In applying CCFL as a backlight for LCD, a direct light type in which a plurality of cold cathode fluorescent lamps are mounted under the liquid crystal panel and a diffusion plate is installed between the cold cathode fluorescent lamp and the liquid crystal panel, and the side of the liquid crystal panel An edge light method is mainly used in which a cold cathode fluorescent lamp is mounted on the light source and the light emitted from the cold cathode fluorescent lamp is distributed to the entire LCD screen using a transparent light guide panel. However, due to the problem that light loss occurs and the light utilization efficiency is low, the overall structure is complicated, the production cost is high, and the uniformity of luminance is limited.

The surface light source device includes an upper substrate and a lower substrate disposed to face each other at predetermined intervals, and a plurality of partition walls are provided between the substrates disposed to face each other. The barrier ribs are arranged in parallel at equal intervals to form a discharge space, a discharge gas is injected into the discharge space, and a pair of electrodes for applying a voltage to the discharge gas is provided outside or inside both edges of the substrate. .

On the other hand, when a discharge voltage is applied to the electrodes, a barrier discharge is generated in the discharge spaces, and the ultraviolet rays generated by the discharge excite the phosphor to generate visible light.

In general, in the surface light source device, the electrode is positioned at the outermost end of the surface light source in order to secure an effective light emission area. Will quickly rise, and when off, the temperature will drop quickly. As such, mercury is adsorbed to the electrode part due to the temperature difference between the electrode part and the discharge part, and a difference in mercury content occurs in the electrode part and the discharge part due to the mercury accumulated in the electrode part when the surface light source is used for a long time. Due to the difference in mercury content, the luminance difference between the electrode part and the discharge part is generated, which lowers the brightness uniformity of the entire surface light source, and the mercury accumulated in the electrode part is invalidated by acceleration due to the application of an electric field. The problem of shortening the lifetime of a surface light source has arisen by the increase.

Accordingly, the present invention is to solve the above conventional problems, the object of the present invention is to discharge the heat of the discharge portion to induce the adsorption of mercury at any position of the discharge portion to reduce the amount of mercury concentrated in the electrode portion The present invention provides a surface light source device and a backlight device using the same.

Another object of the present invention is to provide a surface light source device and a backlight device using the same that can solve the non-uniformity of the luminance due to the difference in the mercury content of the discharge portion and the electrode portion.

Still another object of the present invention is to provide a surface light source device capable of long life and a backlight device using the same.

In order to achieve the above object, the present invention provides a light source body having a discharge portion composed of a plurality of channels, and a pair of electrodes provided at both ends of the light source body to apply a voltage to the discharge gas injected into the discharge portion. In the surface light source device containing,

When the surface light source device is turned off, the light source body is provided on the rear surface of the light source body so as to cross the plurality of channels between the pair of electrodes so as to induce the adsorption of mercury in the discharge unit by emitting heat from the discharge unit. Disclosed is a surface light source device including at least one auxiliary member having a higher thermal conductivity than glass constituting a back substrate of the substrate.

In addition, the present invention is a backlight device employing a surface light source,

A light source body having a discharge portion including a plurality of channels, and having a one-phase electrode for applying a voltage to the discharge gas injected into the discharge portion, the light source body crossing the plurality of channels between the electrodes; A surface light source device provided on a rear surface of the light source body and including at least one auxiliary member having a higher thermal conductivity than glass forming a rear substrate of the light source body;

Upper and lower cases accommodating the surface light source device;

An optical sheet provided between the surface light source device and the upper case; And

Disclosed is a backlight device including an inverter for driving a surface light source device by applying a discharge voltage to the electrode.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In describing the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

According to the present invention, when the electrode provided to the surface light source device turns off the surface of the surface light source device, the electrode portion has a function of lowering the temperature relative to the discharge portion, so that mercury is concentrated on the electrode portion. In consideration of this, it should be noted that the surface light source device is provided with an auxiliary member to assist heat dissipation at any position of the discharge portion.

As shown in Figures 1 to 3, the surface light source device according to a preferred embodiment of the present invention is composed of at least one auxiliary member 200 for dissipating heat of the discharge portion is provided on the back of the light source body 100 do. 1 to 3 show that three auxiliary members are provided, but more or fewer auxiliary members may be provided.

Referring to FIG. 1, the light source body 100 includes a front substrate 110 and a rear substrate 120. The front substrate 110 is formed integrally with a plurality of partition walls, the rear substrate is formed in a flat plate shape, the front substrate 110 and the rear substrate 120 are opposed to each other made up of a plurality of channels (140) The discharge space is formed. In addition, a pair of electrodes 130 and 130 ′ for applying a voltage to the discharge space are provided at both ends of the light source body 100 so as to be located at both ends of the channel 140. The pair of electrodes 130 and 130 ′ are disposed across the plurality of channels 140 at both ends of the light source body 100 to apply voltage to each channel.

2 and 3, three auxiliary members 200a, 200b and 200c provided are provided on the rear surface of the rear substrate 120 to be positioned between the pair of electrodes 130 and 130 ′. In addition, the three auxiliary members 200a, 200b, and 200c provided are parallel to the electrodes 130 and 130 ′, and traverse orthogonally to the plurality of channels 140 provided in the light source body 100. It is arranged to extend continuously from one side end (100a) of the (100) to the other end (100b). Preferably, one of the three auxiliary members (200a, 200b, 200c) of the auxiliary member (200a) is provided to cross the plurality of channels 140 in the central portion of the light source body 100 discharge portion 30 ) To compensate for the lack of mercury, and the remaining two auxiliary members 200b and 200c are provided to be positioned adjacent to the electrodes 130 and 130 'at both ends of the light source body 100 to concentrate the mercury concentrated on the electrode unit 400. It will prevent adsorption.

In more detail, when the auxiliary member is made of a material having a higher thermal conductivity than the glass constituting the front glass and the rear glass, the corresponding part provided with the auxiliary member when the lamp is turned off is provided on the other part of the discharge part. The temperature drops quickly. On the other hand, when the lamp is extinguished, mercury tends to be absorbed by being moved to a portion having a low temperature, so that mercury is adsorbed at the center and both ends of the discharge portion provided with the auxiliary member. Although the electrode part has a lower temperature than the center part and both ends of the discharge part, mercury moving inside the discharge part is first adsorbed to the center part and both end parts of the discharge part located near the discharge part. The amount can be reduced. Moreover, since the electrode is made of silver or copper having high thermal conductivity, but is attached at a low temperature, the organic binder is included in the electrode, so that the thermal conductivity is lower than that of pure silver or copper.

Preferably, the auxiliary member is made of a material having a thermal conductivity higher than that of the glass constituting the rear substrate (approximately 0.65 W / mk), and the auxiliary member acts as a floating electrode, resulting in uneven brightness. It is made of a material with high resistance to prevent it. For example, the auxiliary member may be made of carbon tape or Ni, 42Ni Alloy, Fe, or the like.

The auxiliary members 200a, 200b, and 200c may be formed of a tape having an adhesive layer on one surface thereof and may be attached to the rear substrate 120, and the two auxiliary members disposed adjacent to the electrodes 130 and 130 ′. 200b and 200c have a separation distance D of at least 30 mm from the electrodes 130 and 130 '. When the auxiliary members 200b and 200c are attached to the electrodes 130 and 130 'to have a separation distance D within 30 mm, there is a high likelihood that mercury is adsorbed to the electrode unit 400 as before. Meanwhile, the auxiliary members 200a, 200b, and 200c are provided to have a width of 0.1 to 10 mm. If the width of the auxiliary member is less than 0.1mm, the amount of mercury adsorbed to the auxiliary member is less effective, and if the width of the auxiliary member is larger than 10mm, the shadow of the auxiliary member in the light emitting portion of the front substrate 110 that emits visible light In this case, the luminance is partially lowered and the distance from the diffuser is not shown, thereby acting as a factor that inhibits the slimming of the surface light source device.

Referring to the operation of the auxiliary member as follows.

As described above, the auxiliary members 200a, 200b, and 200c attached to the rear substrate 120 provide a function of emitting heat generated by the driving of the surface light source device to the outside. That is, the surface light source device is driven by a method of emitting light by exciting electrons of gases injected into the surface light source with a high driving voltage, thereby increasing the internal temperature. Then, when the surface light source device is turned off, the auxiliary members 200a, 200b, and 200c attached to the rear substrate 120 are located at the corresponding portions. The heat is released to the outside, so that the part has a lower temperature than other parts of the discharge part, where the vaporized mercury is adsorbed and collected in the part. As such, the mercury adsorbed first to the corresponding portions to which the auxiliary members 200a, 200b, and 200c are attached cannot move to the electrode part, thereby reducing the amount of mercury adsorbed to the electrode part. In addition, the mercury adsorbed to the corresponding part is vaporized again when the surface light source device is turned on, thereby increasing the concentration of the mercury vapor to improve brightness. Therefore, when the auxiliary member is attached to a relatively low portion of the discharge portion 300 of the surface light source device, it is possible to provide a surface light source device with improved luminance uniformity by compensating the low luminance partially.

4 is an exploded perspective view of the backlight device using the surface light source device provided with an auxiliary member. A backlight device of the present invention will be described with reference to FIG. 4.

As shown in FIG. 4, the backlight device according to the present invention includes a surface light source device 500, upper and lower cases 515 and 510, an optical sheet 530, and an inverter 540.

The surface light source device 500 employed in the backlight device is configured in the same manner as the surface light source device 500 of FIG. 1, and thus a detailed description thereof will be omitted.

Referring to FIG. 4, the lower case 510 is provided with an accommodation space to safely store the surface light source device 500. The upper case 515 is coupled to the lower case 510 to safely store the surface light source device 200 and the optical sheet 530. The inverter 540 is disposed on a rear surface of the lower case 510 to generate a discharge voltage for driving the surface light source device 200. The discharge voltages are respectively applied to the electrodes of the surface light source device 300 by wires. The optical sheet 530 may be formed of a diffusion plate for uniformly diffusing the light emitted from the surface light source device 500 and a prism for imparting the straightness of the diffused light.

The surface light source device and the backlight device using the same of the present invention described above are not limited to the above-described embodiments and drawings, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. Will be apparent to those of ordinary skill in the art.

As described above, the present invention prevents the adsorption of mercury concentrated on the electrode part by using the auxiliary member, thereby reducing the amount of mercury consumed, thereby extending the life of the surface light source device. In addition, it is possible to provide a surface light source device having an improved luminance uniformity and a backlight device using the same by preventing a decrease in luminance due to lack of mercury in the discharge unit.

Claims (8)

In the surface light source device including a light source body having a discharge portion composed of a plurality of channels, and electrodes provided at both ends of the light source body to apply a voltage to the discharge gas injected into the discharge portion, When the surface light source device is turned off, the heat is discharged from the discharge unit to induce the adsorption of mercury in the discharge unit is provided on the rear of the light source body to cross the plurality of channels between the electrodes, the rear of the light source body And at least one auxiliary member having a higher thermal conductivity than glass constituting the substrate. The method of claim 1, The auxiliary member may cross the plurality of channels at right angles, and may be disposed to continuously extend from one end of the light source body to the other end. The method of claim 1, The auxiliary member is composed of a tape-like member having an adhesive layer on one surface, the surface light source device, characterized in that attached to the light source body. The method of claim 1, And the auxiliary member is provided to have a separation distance from the electrodes by at least 30 mm or more. The method of claim 1, The auxiliary member is a surface light source device characterized in that it has a width of 0.1 ~ 10mm. The method of claim 1, The auxiliary member is composed of three auxiliary members, One auxiliary member of the three auxiliary members is provided to traverse the plurality of channels at the center of the light source body, And the remaining two auxiliary members of the three auxiliary members traverse the plurality of channels at both ends of the light source body and are provided to maintain a predetermined distance from the respective electrodes. In a backlight device employing a surface light source, A light source body having a discharge portion including a plurality of channels, and having a one-phase electrode for applying a voltage to the discharge gas injected into the discharge portion, the light source body crossing the plurality of channels between the electrodes; A surface light source device provided on a rear surface of the light source body and including at least one auxiliary member having a higher thermal conductivity than glass constituting the rear substrate of the light source body; Upper and lower cases accommodating the surface light source device; An optical sheet provided between the surface light source device and the upper case; And And an inverter configured to drive the surface light source device by applying a discharge voltage to the electrode. The method of claim 7, wherein The auxiliary member may cross the plurality of channels at right angles, and may be disposed to continuously extend from one end of the light source body to the other end.

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