JP2008186683A - Planar light-emitting lamp and liquid-crystal display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar light-emitting lamp that achieves improvement in light-emission uniformity and in luminance characteristics by securing a light-emitting part. <P>SOLUTION: The planar light-emitting lamp is provided with a front transparent substrate, a rear substrate facing the front transparent substrate across a discharge space, a large number of partition walls, which are arranged between the front transparent substrate and the rear substrate so as to split the discharge space into a large number of discharge channels, and a phosphor formed inside the discharge space. The partition walls are formed such that the ratio of the curvature radius (R) of the upper part of each partition wall to the width (W) of the partition wall, that is, (R/W) ranges from 0.1 to 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a surface-emitting lamp, and more particularly to a surface-emitting lamp that secures a light-emitting portion to improve the uniformity and luminance characteristics of light emission. The present invention also relates to a liquid crystal display device using the surface emitting lamp.

  As a lamp used in various illumination devices and display devices, a cold cathode fluorescent lamp (CCFL) is mainly used. Such a cold cathode light-emitting lamp is classified into an internal electrode lamp and an external electrode lamp according to the installation position of the electrodes. In the internal electrode lamp, an electrode is installed in a glass tube in which discharge gas and vaporized mercury are enclosed, and a phosphor is formed on the inner surface of the glass tube. In contrast, in the external electrode lamp, an electrode is installed outside the glass tube, and a phosphor is formed on the inner surface of the glass tube.

  When a high voltage AC signal is applied to the internal electrode of the internal electrode lamp, an electric field is applied between the electrodes to cause plasma discharge. The electrons generated at this time excite mercury to generate ultraviolet rays, and the ultraviolet rays excite and transition by the ultraviolet rays to generate visible light.

  In contrast, when a high-voltage AC signal is applied to the external electrode of the external electrode lamp, a plasma discharge occurs between the two electrodes in the glass tube to generate electrons, which are excited by mercury to fluoresce. Lights the body. In this external electrode lamp, wall charges are formed on the surface of the glass tube in the vicinity of the electrode in the glass tube by plasma discharge, and plasma discharge is generated at a relatively low voltage using this wall charge. There is an advantage that it is driven with efficiency and an advantage that a large number of external electrode lamps can be driven by one inverter because the voltage drop is very small.

  On the other hand, the liquid crystal display device displays an image by adjusting the light transmittance of the liquid crystal cell according to the video signal. An active matrix type liquid crystal display device is advantageous in displaying moving images because a switching element is formed for each liquid crystal cell. As the switching element, a thin film transistor (hereinafter referred to as “TFT”) is mainly used.

  Since the liquid crystal display device is not a self-luminous element, a separate backlight unit is required. The backlight unit of a liquid crystal display device includes an edge-light system that converts light from a lamp installed at one end into a surface light source using a light guide plate and irradiates the liquid crystal display panel, and a liquid crystal display panel There is a direct light system in which a liquid crystal display panel is irradiated with light using a large number of lamps installed below.

  Recently, research and development has been actively conducted on surface emitting lamps (FFLs) that have higher luminous efficiency and luminous brightness than those of the existing edge light system or direct light system and are excellent in the uniformity of the brightness.

  FIG. 1 is a diagram showing a schematic structure of a surface emitting lamp. Referring to FIG. 1, the surface emitting lamp includes a front transparent substrate 1, a rear substrate 2, a partition wall 4 that partitions the plasma discharge channel 8 between the front transparent substrate 1 and the rear substrate 2, and the interior of the plasma discharge channel 8. And the electrodes 3a and 3b formed on the outer surface of the back substrate 2 and having different polarities. An insulating layer 7 is further provided on the electrode 3a formed on the back substrate 2 to insulate the electrode 3a.

  The electrodes 3a and 3b may be formed to face the side surfaces of the respective plasma discharge channels 8.

  An inert gas such as argon (Ar), neon (Ne), xenon (Xe) and gaseous mercury Ag are uniformly injected into the plasma discharge channel 8.

  The partition wall 4 has a height of several mm to several tens mm, and plays a role of partitioning the plasma discharge channel 8 between the front transparent substrate 1 and the rear substrate 2. Further, by forming the partition wall 4 so that both side surfaces have a gradient or curvature, the light is reflected so that the light emitting region is further widened.

  The phosphor 5 plays a role of emitting visible light by emitting light from mercury excited by electrons generated by plasma discharge.

  An AC voltage is applied to the electrodes 3a and 3b so that a discharge can occur in the plasma discharge channel 8.

  A glass edge wall 9 is sandwiched between the front transparent substrate 1 and the rear substrate 2 at the edge of such a surface emitting lamp, and the glass edge wall is bonded to the front transparent substrate 1 and the rear substrate 2 by a sealant.

  FIG. 2 is an enlarged view of the conventional partition shown in the area A of FIG. In FIG. 2, the phosphor 5 is not shown in order to facilitate understanding of the optical path.

  Referring to FIG. 2, the upper surface of the conventional partition wall 4 is formed without a curvature, and a dark portion D where light is not reflected is generated. Accordingly, there is a problem that uniform light emission and luminance cannot be achieved over the entire surface of the surface emitting lamp.

  Therefore, the present invention was created to solve the above-described problems, and the object of the present invention is to obtain a surface light emission that secures a light emitting portion and improves the uniformity of light emission and the luminance characteristics. To provide a lamp.

  Another object of the present invention is to provide a liquid crystal display device using the surface-emitting lamp as a backlight.

  To achieve the above object, a surface emitting lamp according to the present invention includes a front transparent substrate, a rear substrate facing the front transparent substrate across a discharge space, and between the front transparent substrate and the rear substrate. A plurality of barrier ribs arranged to divide the discharge space into a plurality of discharge channels, and a phosphor formed in the discharge space, the barrier rib having a radius of curvature of an upper portion of the barrier rib with respect to a width (W) of the barrier rib. It is formed so that the ratio (R / W) of (R) has a value of 0.1 to 4.

  Preferably, the R / W has a value of 0.13 to 2.83.

  The surface emitting lamp according to the present invention is disposed between the front transparent substrate, the rear substrate facing the front transparent substrate across the discharge space, the front transparent substrate and the rear substrate, and the discharge space. A plurality of barrier ribs that divide the barrier rib into a plurality of discharge channels, and a phosphor formed in the discharge space, wherein the barrier ribs have a radius of curvature (R) of 0.15 mm to 6 mm at the top of each barrier rib. Formed to have.

  Preferably, the curvature radius of the upper part of each partition has a value of 0.2 mm to 4.25 mm.

  Further, the surface emitting lamp according to the present invention faces the rear substrate and the rear substrate across the discharge space, but is bonded to the rear substrate at one or more portions, and the discharge space is divided into a number of discharge channels. Including a front transparent substrate having a bent shape so that it can be divided into two parts, and a phosphor present inside the discharge space, and a width of a portion where the front transparent substrate is bonded to the rear substrate to form a partition wall A ratio (R / W) of a radius of curvature (R) of a portion where the front transparent substrate is bonded to the rear substrate with respect to (W) is formed to have a value of 0.15 to 4.25.

  Preferably, the R / W has a value of 0.15 to 2.5.

  Furthermore, the surface emitting lamp according to the present invention faces the rear substrate and the rear substrate across the discharge space, but is bonded to the rear substrate at one or more portions, and the discharge space is connected to a plurality of discharge channels. Including a front transparent substrate having a bent shape so that it can be divided into two, and a phosphor present inside the discharge space, and a radius of curvature (R) of a portion where the front transparent substrate is bonded to the rear substrate. It has a value of 0.15 mm to 4.25 mm.

  Preferably, the radius of curvature (R) of the portion where the front transparent substrate is bonded to the rear substrate has a value of 0.15 to 2.5.

  The front substrate is formed of a glass material, and the back substrate is formed of a metal material or a ceramic material.

  The liquid crystal display device according to the present invention includes the above-described surface emitting lamp; and a liquid crystal display panel that displays an image by modulating the light from the surface emitting lamp by electrically controlling the liquid crystal according to video data. And comprising.

  As described above, the surface-emitting lamp according to the present invention can improve the luminance characteristics by securing the light-emitting surface by manufacturing the upper surface of the partition wall in a round shape having a predetermined curvature radius. In addition, by adjusting the radius of curvature, the straightness of light can be improved and the light emission uniformity can be improved.

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

  Referring to FIG. 3, the surface emitting lamp according to the embodiment of the present invention includes a front transparent substrate 11, a rear substrate 12, and a partition wall 14 that partitions the plasma discharge channel 18 between the front transparent substrate 11 and the rear substrate 12. The phosphor 15 formed inside the plasma discharge channel 18 and the electrodes 13a and 13b formed on the outer surface of the back substrate 12 and having different polarities are provided. Then, an insulating layer 17 is further provided on the electrode 13a formed on the back substrate 12, and the electrode 13a is insulated.

  The electrodes 13a and 13b may be formed to face the side surfaces of the respective plasma discharge channels 18.

  For example, an inert gas such as argon (Ar), neon (Ne), and xenon (Xe) and gaseous mercury (Hg) are uniformly injected into the plasma discharge channel 18.

  The barrier ribs 14 have a height of several mm to several tens mm, and serve to partition the plasma discharge channel 18 between the front transparent substrate 1 and the rear substrate 12. Further, the partition wall 14 is formed such that both side surfaces have a gradient or concave curvature, so that light is reflected so that the light emitting region becomes wider. The partition wall 14 is formed so that the upper surface has a predetermined radius of curvature R. If the partition wall 14 is not formed so as to have a concave curvature or gradient on both side surfaces, but formed in a hemispherical shape having only a predetermined radius of curvature as a whole, the contact area between the partition wall 14 and the back substrate 12 becomes wide. Therefore, the overall light emitting area of the surface emitting lamp is reduced. Therefore, the partition wall 14 according to the present invention is formed so that the upper surface has a predetermined radius of curvature R. In addition, since both side surfaces of the partition wall 14 are formed to have a gradient or concave curvature, the light emitting area of the surface emitting lamp can be further ensured.

  The phosphor 15 plays a role of emitting visible light by emitting light from mercury excited by electrons generated by plasma discharge.

  An AC voltage is applied to the electrodes 13a and 13b so that a discharge can occur in the plasma discharge channel 18.

  A glass edge wall 19 is sandwiched between the front transparent substrate 11 and the rear substrate 12 at the edge of such a surface emitting lamp. The glass edge wall 19 is bonded to the front transparent substrate 11 and the rear substrate 12 by a sealant. The front transparent substrate 11 is made of a glass material through which light can pass, and the back substrate 12 is made of a metal material or a ceramic material.

  FIG. 4 is an enlarged view of the partition wall according to the present invention shown in the area B of FIG. In FIG. 4, the phosphor 15 is not shown in order to facilitate understanding of the optical path.

  Referring to FIG. 4, the partition wall 14 according to the present invention is formed so that the upper surface in contact with the front transparent substrate 11 has a round shape with a predetermined curvature radius R. Thereby, the contact surface between the front transparent substrate 11 and the partition wall 14 having a round shape is narrower than the contact surface between the conventional front transparent substrate 1 and the partition wall 4 shown in FIGS. Therefore, the light emitting portion coated with the phosphor 15 can be formed on the upper surface of the partition wall 14 more widely. In addition, the amount of light in the non-light emitting region can be supplemented so that the light path on the upper surface of the round partition 14 proceeds to the non-light emitting region on the upper surface of the partition 14. Thereby, the light quantity in a light emission area | region and a non-light emission area | region becomes uniform.

  FIGS. 5 a to 5 e are diagrams showing the pattern of the partition walls used when measuring the luminance with the curvature radius R. FIGS. [Table 1] shows data obtained by measuring the luminance characteristics by the curvature radius R. 5a to 5e, the C value is the width of the contact surface between the partition wall 14 and the front transparent substrate 11. Adhesion between the partition wall 14 and the front transparent substrate 11 is usually performed with a sealant. The experimental data was analyzed assuming that the sealant C that bonds the partition wall 14 and the front transparent substrate 11 is a 100% light absorber. In the experiment, the width of the partition wall 14 was fixed at 1.5 mm, and the distance between the partition walls 14 was fixed at 5 mm. The luminance characteristic is a value measured from the front of the surface emitting lamp. In the experiment, the width of the fixed partition wall 14 is the width at the inflection point between the upper part and the middle part of the partition wall 14.

  [Table 1] is a table showing the luminance characteristic efficiency of the upper part of the partition wall by changing the curvature with respect to the partition wall.

  Referring to [Table 1], when the partition wall width (W) is 1.5 mm and the upper curvature (R) has a value of 0.15 to 6 mm, the luminance characteristics are excellent, and this curvature is applied. When a surface-emitting lamp is manufactured, the same luminance as that without a partition can be obtained in the presence of the partition. Moreover, when the curvature (R) of the upper part is 0.2 mm to 4.25 mm, it is possible to obtain a brightness comparable to that where there is no partition wall.

  That is, when the ratio of the radius of curvature (R) of the upper part of the partition wall to the width (W) of the partition wall, that is, R / W has a value of 0.1 to 4, the brightness of the upper part of the partition wall is equivalent to the front brightness without the partition wall. It turns out that it is. And when R / W has a value of 0.1-4, it turns out that the brightness | luminance of a partition upper part is substantially equal to the brightness | luminance in the place without a partition, or it is larger than it. Moreover, when R / W is 0.13-2.83, the brightness | luminance comparable to the place without a partition can be obtained further.

  On the other hand, when R / W has a value exceeding 4, it can be seen that the luminance characteristics are inferior.

  A vacuum state is formed in the plasma discharge channel 18 for discharge. At this time, the partition wall 14 must be able to withstand the generated pressure. For this reason, the contact area between the back substrate 12 and the partition wall 14 is made relatively larger than the contact area between the front substrate 11 and the partition wall 14.

  Thus, by manufacturing the upper part of the partition wall 14 in a round shape, the light in the non-light emitting region and the light emitting region is made uniform, the light emitting uniformity is improved, the light emitting area is further widened, and the luminance characteristics are improved. .

  On the other hand, the present invention can be applied not only to a surface emitting lamp in which a partition wall is separately formed, but also to a surface emitting lamp in which the partition wall is manufactured by, for example, a glass molding method. That is, the present invention can also be applied to a glass molding surface emitting lamp formed by bonding a front transparent substrate having a curved shape obtained by forming and bending a flat glass to a flat rear substrate. Also in this case, the front transparent substrate is bonded to the rear substrate to serve as a partition wall, but the portion where the front transparent substrate is bonded to the rear substrate is not a linear form, and is curved like the partition pattern according to the present invention. Configured in shape. In this case, when the ratio (R / W) between the width (W) of the dark part forming the partition and the radius of curvature (R) of the portion where the front transparent substrate is bonded to the rear substrate has a value of A to B, In addition to excellent characteristics, when a surface emitting lamp is manufactured by applying this curvature, it is possible to obtain a luminance equivalent to that in the dark portion and in the dark portion.

  FIG. 6a shows a structure of a glass molding surface emitting lamp in which a conventional front substrate bent into a square shape is bonded to a flat rear substrate, and FIG. 6b shows a front substrate in a bent shape according to the present invention. The joining part of FIG. 4 shows the structure of a glass molding surface emitting lamp having a curved surface shape.

  Referring to FIG. 6b, the ratio (R / W) of the width (W) at which the front transparent substrate 61 is bonded to the rear substrate 62 to form the partition and the curvature radius (R) of the curved surface of the bonded portion is A. A case having a value of ~ B is shown. In this case, the area of the portion where the front transparent substrate 61 is bonded to the rear substrate 62 can be irradiated with the same amount of light as the other areas.

  [Table 2] is a table showing the luminance characteristic efficiency of the glass joint portion by changing the curvature of the front glass when glass molding is used.

  Referring to [Table 2], when the dark portion width (W) is 1 mm and the front substrate curvature (R) has a value of 0.15 to 4.25 mm, the luminance characteristics are excellent and this curvature is applied. Thus, when the surface emitting lamp is manufactured, the same luminance can be obtained when the front substrate is bonded to the rear substrate as when the front substrate is not bonded to the rear substrate. Further, when the curvature (R) of the front substrate has a value of 0.15 to 2.5 mm, it is possible to obtain luminance comparable to that where the front substrate is not joined to the rear substrate.

  That is, when the ratio (R / W) of the radius of curvature (R) of the bonded portion of the front substrate to the width (W) of the dark portion has a value of 0.15 or more and 4.25 or less, the luminance of the upper portion of the bonded portion of the substrate Is equivalent to the front luminance. And when R / W has a value of 0.15-2.5, it turns out that the brightness | luminance of the joined part is substantially equal to a front brightness | luminance, or is larger than it.

  On the other hand, when R / W has a value exceeding 4.25, it turns out that the luminance characteristic is inferior.

  The surface emitting lamp according to the present invention can be used as a light source of a non-light emitting element such as a general lighting device or a liquid crystal display device. In addition, the liquid crystal display panel of the liquid crystal display device according to the present invention can be realized by any known liquid crystal display panel that modulates light from a surface emitting lamp by electrically controlling liquid crystal according to video data. is there.

  From the above description, it will be understood by those skilled in the art that various changes and modifications can be made without departing from the technical idea of the present invention. Therefore, the technical scope of the present invention is not limited to the contents described in the detailed description of the specification, but should be defined by the claims.

It is a figure which shows the schematic structure of the conventional surface emitting lamp. It is an enlarged view of the A area | region of FIG. It is a figure which shows schematic structure of the surface emitting lamp which concerns on the Example of this invention. FIG. 4 is an enlarged view of a region B in FIG. 3. It is a figure which shows the schematic structure of the partition used in the case of the measurement of the brightness | luminance by a curvature radius (R). It is a figure which shows the schematic structure of the partition used in the case of the measurement of the brightness | luminance by a curvature radius (R). It is a figure which shows the schematic structure of the partition used in the case of the measurement of the brightness | luminance by a curvature radius (R). It is a figure which shows the schematic structure of the partition used in the case of the measurement of the brightness | luminance by a curvature radius (R). It is a figure which shows the schematic structure of the partition used in the case of the measurement of the brightness | luminance by a curvature radius (R). It is a figure which shows the structure of the glass molding surface emitting lamp by which the front board | substrate of the shape bent in the conventional square was bonded together to the flat back board | substrate. It is a figure which shows the structure of the glass molding surface emitting lamp with which the junction part of the bent front substrate which concerns on this invention has a curved surface shape.

Explanation of symbols

1, 11 Front transparent substrate 2, 12 Back substrate 3a, 3b, 13a, 13b Electrode 4, 14 Partition 5, 15 Phosphor 7, 17 Insulating layer 8, 18 Plasma discharge channel 9, 19 Glass edge wall

Claims (10)

A front transparent substrate;
A back substrate facing the front transparent substrate across a discharge space;
A plurality of barrier ribs disposed between the front transparent substrate and the rear substrate, and dividing the discharge space into a plurality of discharge channels;
A phosphor formed inside the discharge space,
The surface emitting lamp is characterized in that the partition wall is formed so that a ratio (R / W) of a curvature radius (R) of the partition wall upper portion to a partition wall width (W) has a value of 0.1 to 4. .   2. The surface emitting lamp according to claim 1, wherein the R / W has a value of 0.13 to 2.83. A front transparent substrate;
A back substrate facing the front transparent substrate across a discharge space;
A plurality of barrier ribs disposed between the front transparent substrate and the rear substrate, and dividing the discharge space into a plurality of discharge channels;
A phosphor formed inside the discharge space,
The surface-emitting lamp according to claim 1, wherein the partition wall has a radius of curvature (R) at an upper portion of each partition wall of 0.15 mm to 6 mm.   The surface emitting lamp according to claim 3, wherein a radius of curvature of an upper portion of each partition wall has a value of 0.2 mm to 4.25 mm. A back substrate;
A front transparent substrate facing the back substrate across a discharge space, but having a shape that is bonded to the back substrate at one or more portions and bent so that the discharge space can be divided into a number of discharge channels; ,
A phosphor existing inside the discharge space,
Ratio (R / W) of the radius of curvature (R) of the portion where the front transparent substrate is bonded to the back substrate to the width (W) of the portion where the front transparent substrate is bonded to the back substrate to form a partition wall Is formed so as to have a value of 0.15 to 4.25.   6. The surface emitting lamp according to claim 5, wherein the R / W has a value of 0.15 to 2.5. A back substrate;
A front transparent substrate facing the back substrate across a discharge space, but having a shape that is bonded to the back substrate at one or more portions and bent so that the discharge space can be divided into a number of discharge channels; ,
A phosphor existing inside the discharge space,
A surface emitting lamp, wherein a radius of curvature (R) of a portion where the front transparent substrate is bonded to the rear substrate has a value of 0.15 mm to 4.25 mm.   The surface emitting lamp according to claim 7, wherein a radius of curvature (R) of a portion where the front transparent substrate is bonded to the rear substrate has a value of 0.15 to 2.5.   The surface emitting lamp according to any one of claims 1 to 8, wherein the front substrate is formed of a glass material, and the back substrate is formed of a metal material or a ceramic material. A surface-emitting lamp according to any one of claims 1 to 8,
A liquid crystal display device comprising: a liquid crystal display panel that displays an image by electrically controlling a liquid crystal according to video data and modulating light from the surface emitting lamp.

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