KR20060050082A - Cold cathode fluorescent lighting discharge tube device - Google Patents

Abstract

The increase in the tube wall temperature of the discharge tube when the tube current of the cold cathode fluorescent discharge tube device or the number of discharge tubes is increased is suppressed.

Stretching between the holder 1 formed of the material with high heat dissipation, the discharge tube 2 which has the both ends 3 supported by the holder 1, and the both ends 3 of the discharge tube 2 The heat conductive bracket 5 attached to the intermediate portion 4 and closely attached to the holder 1 is installed in the cold cathode fluorescent discharge tube apparatus. The heat generated from the discharge tube 2 is released to the outside through the bracket 5 and the holder 1 thermally connected to the bracket 5, thereby preventing the temperature rise of the discharge tube 2.

Description

Cold Cathode Fluorescent Discharge Tube Device {COLD CATHODE FLUORESCENT LIGHTING DISCHARGE TUBE DEVICE}

1 is a perspective view of a discharge tube device according to the present invention.

2 is a perspective view of a bracket used in the discharge tube device of FIG.

3 is a cross-sectional view of the discharge tube device of FIG.

4 is a perspective view of a backlight using the discharge tube device of FIG.

5 is a cross-sectional view showing another embodiment of the bracket of the present invention.

6 is a cross-sectional view showing another embodiment in which a reflector is provided.

7 is a cross-sectional view showing another embodiment using the bracket of the fluid.

8 is a cross-sectional view showing another embodiment of a bracket in which a spacer is integrally formed.

<Description of Symbols for Main Parts of Drawings>

1 holder 2 discharge tube

2a: glass tube 3: end

4 middle part 5 bracket

6 reflector 1e opening surface

12: external heat sink

The present invention relates to a cold cathode discharge tube device which can discharge heat generated by a cold cathode fluorescent discharge tube device, in particular a cold cathode fluorescent discharge tube, to achieve high luminance and long life.

For example, a backlight having a cold cathode fluorescent discharge tube disposed at a side end of a flat light guide, reflecting light introduced from the discharge tube by a reflective sheet formed on the lower surface of the light guide, and emitting from the top surface of the light guide It is known as disclosed in Patent Document 1 below. The backlight includes a reflective cover surrounding the discharge tube, and includes a first gap formed between the discharge tube and the side end portion of the light guide and a second gap formed between the discharge tube and the curved surface of the reflective cover. Almost equal. In addition, the sum of the first gap and the second gap is made larger than the diameter of the discharge tube, and the light emitted from the discharge tube can be satisfactorily reflected by the reflecting cover to be transmitted to the light guide. Backlights with reflective covers are also disclosed in other publications.

Patent Literature 2 below shows a surface light source device in which the luminance of incident light in the vicinity of the electrode portion is prevented from being lowered without reducing the total amount of light incident on the light guide and the uniform luminance distribution is distributed over the entire emission cross section. The planar light source device includes a linear light source of a discharge tube, a light guide body disposed closely to an incidence end portion in a linear light source, a diffusion member provided on the light guide exit surface side, a reflection member provided on a side opposite to the light guide exit surface, Incidentally, a lamp holder covering a linear light source can be provided, and the incidence efficiency when the inner surface of the lamp holder is the diffuse reflection surface and the other portion is the specular reflection can be increased from the incidence end face of the light guide.

The following patent document 3 shows the backlight which installs the soldering part of a return electric wire in a light source reflector, and strengthens a soldering part. The following Patent Document 4 combines a pair of light guide plates having a right-angled triangular cross section, reflects most of the light introduced from the end surface of the light guide plate in the irradiation direction in line with the net dot, and improves the light utilization efficiency. The planar color light-emitting device which can achieve thinning of a backlight using two light guide plates is shown.

[Patent Document 1]

Japanese Patent Publication No. 6-67025

[Patent Document 2]

Japanese Patent Application Laid-Open No. 8-271895

[Patent Document 3]

Japanese Patent Application Laid-Open No. 10-12026

[Patent Document 4]

Japanese Patent Laid-Open No. 2000-268617

For example, in cold cathode fluorescent discharge tubes used for television monitors and the like, the demand for high luminance is high. In order to increase the brightness of the discharge tube, it is conceivable to increase the tube current (lamp current) per one or increase the number of discharge tubes arranged at the side end of the light guide. However, since the cold cathode fluorescent discharge tube has a characteristic that the luminance of the discharge tube is lowered when the temperature of the tube wall temperature of the glass tube is exceeded, even if the number of tube currents or discharge tubes is simply increased, the tube wall temperature of the glass tube increases, resulting in high luminance. Can't get it. Therefore, it is necessary to improve the brightness of the cold cathode fluorescent discharge tube by suppressing the increase in the tube wall temperature of the glass tube and lighting it at the optimum temperature.

Accordingly, an object of the present invention is to provide a cold-cathode fluorescent discharge tube apparatus capable of achieving high luminance and long life by suppressing an increase in the tube wall temperature of a glass tube even if the number of discharge tubes is increased or the tube current is increased.

The cold cathode fluorescent discharge tube device according to the present invention includes a cold cathode fluorescent discharge tube (2) having a holder (1) and a glass tube (2a), and both ends 3 of the cold cathode fluorescent discharge tube (2) are holders. Supported by (1). A plurality of thermally conductive brackets 5 are attached to the glass tube 2a of the cold cathode fluorescent discharge tube 2, and the plurality of brackets 5 are brought into contact with the holder 1 so that heat conduction is possible. Since heat generated from the cold cathode fluorescent discharge tube 2 is discharged to the outside through the bracket 5 and the holder 1 thermally connected to the bracket 5, the temperature rise of the cold cathode fluorescent discharge tube 2 is increased. It can be suppressed. In addition, when the glass tube 2a causes the lamp to flow for a long time in a state where a cooling portion is locally generated by heat dissipation, mercury concentrates on the cooling portion, mercury is depleted at other portions, and the luminance decreases. Since the bracket 5 is in contact with a plurality of places of the glass tube 2a constituting the cathode fluorescent discharge tube 2, the glass tube 2a uniformly radiates at least the entire longitudinal direction of the light emitting region, so that the luminance is partially lowered. I never do that. No movement or deformation occurs in the glass tube 2a of the cold cathode fluorescent discharge tube 2 that is reliably supported by the bracket 5. Moreover, the deformation | transformation of the holder 1 which arises when an external force is applied can be prevented by the bracket 5.

In the embodiment of the present invention, the thermally conductive bracket 5 is brought into contact with the entire longitudinal direction of the glass tube 2a of the cold cathode fluorescent discharge tube 2 so that the bracket 5 is brought into thermal contact with the holder 1. .

Embodiment of the Invention

An embodiment of a cold cathode fluorescent discharge tube device according to the present invention applied to a backlight system will now be described with reference to FIGS. 1 to 8.

As shown in FIG. 1, the cold cathode fluorescent discharge tube device according to the present invention includes a holder 1 and a cold cathode fluorescent discharge tube 2 having a connector case 7 and a glass tube 2a provided at both ends of the holder 1. ). Both ends 3 of the cold cathode fluorescent discharge tube 2 are supported by the connector case 7. The glass tube 2a is formed in a straight cylindrical shape having an inner diameter of 2 mm and a total length of 310 mm, and is filled with rare gas and mercury vapor therein, and is not shown. However, the glass tube 2a is fixed to opposite ends of the glass tube 2a. A pair of electrodes, a fluorescent film formed on the inner wall of the glass tube 2a, and a pair of terminals electrically connected to the electrodes and drawn from both ends of the cold cathode fluorescent discharge tube 2 are provided. Since the pair of terminals are connected to the conductive wire 8 in the connector case 7 and to the discharge circuit lighting inverter circuit (not shown) through the conductive wire 8, an inverter circuit for lighting the discharge tube is generated. The high voltage is applied to a pair of terminals of each cold cathode discharge tube 2. The inner wall surface 1a of the holder 1 which consists of the upper surface 1b, the side surface 1c, and the bottom surface 1d comprises the light reflection surface which reflects a part of the light emitted from the cold cathode discharge tube 2. .

The holder 1 is formed of the following metal material or alloy of such metal material having high thermal conductivity and good heat dissipation.

Metal thermal conductivity (kcal / m · h · ℃)

Copper (Cu) 332

Aluminum (AI) 196

Magnesium (Mg) 147

Zinc (Zn) 96

As shown in FIG. 1, the cold cathode fluorescent discharge tube 2 is held by six brackets 5 arranged in the holder 1. The bracket 5, which preferably has excellent thermal conductivity and has good light transmittance, is formed of, for example, a rectangular plate material made of silicone resin having a thickness of about 3 mm. As shown in Fig. 2, each bracket 5 is provided with a through hole 15 as a cutout for mounting a pair of discharge tubes 2, and the pair of through holes 15 is a cold cathode discharge tube ( It is almost the same as the cross-sectional shape of the glass tube 2a which comprises 2). The inner diameter of the through hole 15 of the circular cross section is substantially the same as the outer diameter of the glass tube 2a constituting the cold cathode fluorescent discharge tube 2, and is formed, for example, with a diameter of about 2 mm, When the cold cathode fluorescent discharge tube 2 is mounted in the through-hole 15, the middle portion 4 extending between both ends 3 of the cold cathode fluorescent discharge tube 2, that is, light emission of the glass tube 2a The outer wall of the region is in contact with the inner wall of the through hole 15. As a result, the cold cathode fluorescent discharge tube 2 can be reliably held at a predetermined position in the holder 1 and the heat generated by the glass tube 2a can be transmitted to the bracket 5. As illustrated in FIG. 1, six brackets 5 are mounted in the holder 1 at substantially equal intervals between the one end and the other end, and the cold cathode fluorescent discharge tube 2 inserted into the through hole 15. The middle part 4 of) is supported over almost the entire length. The top surface 5a, the inner side surface 5b and the bottom surface 5c of the bracket 5 are in contact with the top surface 1b, the side surface 1c and the bottom surface 1d of the holder 1, respectively. (5) is in close contact with the holder (1). The outer side surface 5d of the bracket 5 is exposed to the opening face 1e of the holder 1.

In this embodiment, the clearance length of the opening surface 1e formed between the pair of connector cases 7 (the opposing spacing of the pair of connector cases 7) L is 298 mm, and the bracket 5 The thickness was 3 mm. The brackets 5 arranged at equal intervals between the pair of connector cases 7 are adjacent to each other, and the distance between the brackets 5 and the connector cases 7 disposed at both ends is about 40 mm.

As shown in FIG. 4, a backlight used as a light source such as a liquid crystal display includes a plate-shaped light guide 10 made of a light-transmissive resin material and the like, and the cold cathodes disposed at both ends of the light guide 10. A fluorescent discharge tube device is provided. The pair of cold cathode fluorescent discharge tube devices are disposed on one end surface 10c and the other end surface 10d of the light guide 10, respectively, and the holder 1 of each cold cathode fluorescent discharge tube device is , Extending along one end face 10c of the light guide 10 and the other end face 10d, and the outer side surface 5d of the connector case 7 and the six brackets 5, The one end surface 10c and the other end surface 10d of the light guide 10 are respectively contacted. Accordingly, the cold cathode fluorescent discharge tube 2 is surrounded by the end faces 10c and 10d of the light guide 10 and the holder 1. It is preferable that the light guide 10 is formed from various resin materials which are excellent in light transmittance and heat resistance, for example, acrylic resin.

Although the illustration is omitted on the other main surface 10e of the light guide 10, a reflective sheet is attached. In addition, as shown in FIG. 4, since both ends of the outer heat radiation plate 12 arranged on the other main surface 10e side of the light guide 10 are connected to the bottom surface 1d of the holder 1. The cold cathode fluorescent discharge tube 2 is connected to the holder 1 and the external heat dissipation plate 12 via a plurality of brackets 5 in such a manner that heat transfer is possible. The external heat sink 12 is formed of a metal material having good thermal conductivity such as zinc (Zn), aluminum (AI), copper (Cu), and the like, and is transferred from the bracket 5 and the holder 1. It has a function of radiating the heat of the cold cathode fluorescent discharge tube 2 to the outside.

The inner wall 1a of the holder 1 constitutes the surface which reflects the light radiated | emitted from the cold cathode fluorescent discharge tube 2 by apply | coating white paint or chromium plating. However, when the holder 1 itself is formed from a material having high light reflectance, it is not necessary to apply white paint, chromium plating, or the like to the inner wall 1a. Since the inner wall 1a of the holder 1 is a light reflecting surface, the holder 1 constitutes a reflector which guides light to the light guide 10. For this reason, the light emitted to the light guide 10 among the light emitted radially from the cold cathode discharge tube 2 directly enters the light guide 10 from the end faces 10c and 10d, and the cold cathode discharge tube 2 Among the light emitted radially from the light emitted on the holder 1 side, it is incident on the light guide plate 10 from the end faces 10c and 10d after being reflected at the inner wall 1a of the holder 1. Light incident on the light guide plate 10 is transmitted while repeating the reflection inside the light guide plate 10 to emit light in a planar shape from one main surface 10f of the light guide plate 10.

In the cold cathode fluorescent discharge tube device according to the present embodiment, the following effects can be obtained.

[1] Since the heat generated from the discharge tube 2 can be discharged to the outside through the bracket 5 and the holder 1 thermally connected to the bracket 5, the temperature rise of the discharge tube 2 can be suppressed. Can be.

[2] In addition, heat generated from the discharge tube 2 can be radiated to the outside well through the external heat radiating plate 12 connected to the holder 1.

[3] Through the brackets 5 contacting the plurality of cold cathode fluorescent discharge tubes 2 at equal intervals, the cold cathode discharge tubes 2 can be radiated almost uniformly over the entire length direction.

[4] Since the bracket 5 having light transparency is provided, dark portions such as shadows are not formed at the periphery of the bracket 5.

[5] The number of brackets 5 in contact with a plurality of places of the cold cathode fluorescent discharge tube 2 can be increased or decreased, and the amount of heat dissipation of the cold cathode fluorescent discharge tube 2 can be easily adjusted according to the tube current or the like.

[6] Since the intermediate portion 4 of the cold cathode fluorescent discharge tube 2 is securely supported by the plurality of brackets 5, the movement or deformation of the cold cathode fluorescent discharge tube 2 is unlikely to occur, resulting in highly reliable cold A cathode fluorescent discharge tube device can be realized.

[7] Deformation of the holder 1 can be satisfactorily prevented by the plurality of brackets 5 arranged in the holder 1 when an external force or heat is applied to the holder 1.

Embodiment of this invention can be variously changed. For example, as shown in FIG. 5, the protrusion part 5e is integrally formed with the bracket 5 in the top surface 5a and the bottom surface 5c of the bracket 5, and the inner top surface of the holder 1 ( The protrusions 5e may be fitted to the recesses 14 formed on the inner surface 1d and 1b), and the bracket 5 may be detachably attached to the holder 1. When attaching or detaching the projection 5e to the recess 14, the elastic deformation of the inner upper surface 1b and the inner bottom surface 1d itself constituting the holder 1 can be used. On the contrary, the protrusions formed on the inner upper surface 1b and the inner bottom surface 1d of the holder 1 may be detachably fitted to the concave portions formed on the bracket 5. In addition, when the cutout portion 15 is formed in the bracket 5, and the cutout portion 15 is opened on the inner side surface 5b side instead of the through hole, the cold cathode fluorescent discharge tube 2 is connected to the connector case of the holder 1 ( After attaching to 7), the bracket 5 can be inserted from the opening face 1e and attached to the cold cathode fluorescent discharge tube 2.

In addition, in embodiment shown in FIG. 6, the reflector 6 which has reflection surfaces, such as a semi-ellipse cross section and a parabolic cross section, is attached to the inside of the holder 1 separately. The reflector 6 reflects the light emitted from the cold cathode fluorescent discharge tube 2 to the outside of the holder 1, and the bracket 5 is in contact with the reflector 6 constituting a part of the holder 1. As shown in Fig. 7, the cold cathode fluorescent discharge tube 2 may be fitted into the cutout 15 of the bracket 5 formed by molding a fluid such as silicone rubber. At this time, the bracket 5 is in contact with almost the entire length direction of the glass tube 2a constituting the cold cathode fluorescent discharge tube 2. Therefore, almost all of the glass tube 2a constituting the cold cathode fluorescent discharge tube 2 is connected to the holder 1 via the bracket 5.

8, the spacer 16 arrange | positioned between each bracket 5 is integrally formed with the bracket 5, and the some bracket 5 can be handled integrally, and the spacer ( 16) each bracket 5 can be held in a predetermined position in the holder 1.

As another method, the discharge tube device according to the present invention can be applied to a direct backlight system having no light guide plate 10. As another embodiment, the number, shape and material of the bracket 5 can be selected suitably. In order to prevent local cooling of a part of the glass tube 2a constituting the cold cathode fluorescent discharge tube 2, the cold cathode fluorescent discharge tube 2 is formed in a bracket 5 formed by forming a fluid such as silicone rubber. Except in the case of inserting the pin, it is preferable to provide at least three brackets 5 and set the distance between the adjacent brackets 5 to 80 mm or less, preferably 50 mm or less. The bracket 5 may be formed to a thickness of about 1 mm by a metal having excellent conductivity such as copper, aluminum, magnesium, or zinc. In this case, it is preferable that the surface of the bracket 5 be subjected to chromium plating having good light reflectivity or the like so that the bracket 5 becomes a light reflection surface.

[Industry availability]

This invention can be favorably applied to light sources, such as a backlight used for a liquid crystal display, for example.

In the present invention, the following effects can be obtained.

[1] The heat dissipating bracket can prevent the rise of the tube wall temperature of the cold cathode fluorescent discharge tube and maintain the tube wall temperature of the discharge tube at an optimum temperature.

[2] Therefore, even if the number of cold cathode fluorescent discharge tubes is increased or the tube current is increased, the cold cathode fluorescent discharge tubes can be efficiently emitted and high luminance can be achieved.

[3] Since the cold cathode fluorescent discharge tube can be uniformly radiated and cooled in the longitudinal direction, mercury can be maintained in a uniform dispersed state over the entire light emitting region of the discharge tube, and uniform luminance can be obtained.

[4] Even if the lamp is flowed for a long time, no local depletion of mercury occurs, the lamp life is long, and the luminance is not lowered within the lamp warranty lifetime, and a highly reliable cold cathode fluorescent discharge tube device can be realized.

Claims (7)

In the cold cathode fluorescent discharge tube apparatus having a cold cathode fluorescent discharge tube having a holder and a glass tube, and supporting both ends of the cold cathode fluorescent discharge tube by the holder, By mounting a plurality of thermally conductive brackets on the glass tube of the cold cathode fluorescent discharge tube, And a plurality of the brackets are in thermal contact with the holder so as to allow heat conduction. The method of claim 1, And the bracket is in contact with the glass tubes of the cold cathode fluorescent discharge tube at equal intervals. In the cold cathode fluorescent discharge tube apparatus comprising a cold cathode fluorescent discharge tube having a holder and a glass tube, and supporting both ends of the cold cathode fluorescent discharge tube by the holder, A thermally conductive bracket is brought into contact with the entire longitudinal direction of the glass tube of the cold cathode fluorescent discharge tube. Cold cathode fluorescent discharge tube apparatus characterized in that the bracket is in thermal contact with the holder. The method according to claim 1 or 2, The holder has a reflector for reflecting light emitted from the cold cathode fluorescent discharge tube to the outside of the holder, The bracket is a cold cathode fluorescent discharge tube device in contact with the reflector so as to enable heat conduction. The method according to claim 1 or 2, A cold cathode fluorescent discharge tube device in which an external heat sink is connected to the holder. The method according to claim 1 or 2, The bracket is a cold cathode fluorescent discharge tube device having a light transmittance. The method according to claim 1 or 2, A pair of said cold cathode fluorescent discharge tube is held parallel to the opening surface of the said holder, and is hold | maintained at predetermined intervals by the said holder.

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