KR20040022376A - Double-tubes fluorescent lamps - Google Patents

Abstract

PURPOSE: A dual tube fluorescent lamp is provided to achieve a high intensity of a radiation, a high brightness, and a high efficiency by restoring a fault of an external electrode fluorescent lamp. CONSTITUTION: A dual tube fluorescent lamp comprises a first glass tube(11), a second glass tube(10) arranged in the parallel direction of the first glass tube inside the first glass tube, a discharge space formed by sealing a space between the first glass tube and the second glass tube at both ends of the glass tube, fluorescent materials(30,31) deposited on an outer wall of the second glass tube and an inner wall of the first glass tube inside the discharge space, and metal electrodes(20,23) formed on the first glass tube and the second glass tube. A thickness of the fluorescent material deposited on the inner wall of the first glass tube is thinner than a thickness of the fluorescent material deposited on the outer wall of the second glass tube.

Description

Double tube fluorescent lamps {DOUBLE-TUBES FLUORESCENT LAMPS}

The present invention relates to a fluorescent lamp, and more particularly to a double tube fluorescent lamp consisting of two cylindrical glass tubes.

Conventional fluorescent lamps include hot cathode fluorescent lamps (HCFL), cold cathode fluorescent lamps (CCFL), and external electrode fluorescent lamps (EEFL). Divided by.

In the HCFL and CCFL, electrodes are provided at both ends of the discharge space inside the glass tube, and a high voltage is applied to the electrodes to generate light by fluorescence emission by discharge. However, the internal electrode fluorescent lamp has a short lifetime.

Meanwhile, the EEFL seals the glass tube and installs external electrodes on the outer walls of both ends of the glass tube, and the external electrode forms an electric field in the glass tube by capacitive coupling with the glass tube wall, and generates light by gas discharge. In this case, the EEFL has an advantage of longer lamp life than the HCFL or CCFL.

HCF, which has a relatively large diameter of several centimeters, is mainly used when a large amount of light is required, such as a fluorescent lamp for general lighting, or when the amount of power is large. In contrast, CCFLs and EEFLs having a diameter of several mm are used as backlights for high brightness and are used when the amount of power is small.

In general, the diameter of the lamp is related to the amount of light according to the brightness and power capacity. The smaller the diameter is, the higher the luminance can be. However, since the light emitting area of the fluorescent lamp is small, the amount of light is small. On the other hand, the larger the diameter, the lower the luminance, but is applied to a high power lamp having a large amount of light due to an increase in the light emitting area.

In particular, in the case of EEFL, a tube having a diameter of several mm is used to obtain high brightness, but the EEFL has a disadvantage in that a high amount of light can be obtained, but the amount of light is small. Therefore, when the inner diameter of the EEFL is increased, relatively high luminance cannot be obtained.

The present invention has been made to solve the above problems, an object of the present invention is to provide a double tube fluorescent lamp that can provide a high light intensity, high brightness and high efficiency by overcoming the disadvantages of the EEFL.

1A is a perspective view of a double tube fluorescent lamp according to a first embodiment of the present invention.

FIG. 1B is a cross-sectional view taken along X-Y in FIG. 1A.

FIG. 1C is a cross-sectional view taken along the line A-A of FIG. 1B.

FIG. 1D is a cross-sectional view taken along line B-B of FIG. 1B.

1E to 1F are cross-sectional views of a double tube fluorescent lamp according to a modified first embodiment.

2A is a cross-sectional view in the longitudinal direction of a double tube fluorescent lamp according to a second embodiment of the present invention.

FIG. 2B is a cross-sectional view taken along the line C-C in FIG. 2A.

FIG. 2C is a cross-sectional view taken along the line D-D of FIG. 2A.

3A is a cross-sectional view in the longitudinal direction of a double tube fluorescent lamp according to a third embodiment of the present invention.

3B to 3C are cross-sectional views of a double tube fluorescent lamp according to a third modified embodiment.

4A is a perspective view illustrating a double tube fluorescent lamp according to a fourth exemplary embodiment of the present invention.

4B is a cross-sectional view in the length direction of the double tube fluorescent lamp disclosed in FIG. 4A.

4C is a cross-sectional view of the double tube fluorescent lamp of FIG. 4B taken along line E-E.

4D is a cross-sectional view taken along line F-F of FIG. 4B.

5A is a perspective view illustrating a double tube fluorescent lamp according to a fifth exemplary embodiment of the present invention.

5B is a cross-sectional view in the longitudinal direction of the double tube fluorescent lamp disclosed in FIG. 5A.

5C is a cross-sectional view taken along line G-G of FIG. 5B.

FIG. 5D is a cross-sectional view taken along line H-H of FIG. 5B.

6A is a perspective view illustrating a double tube fluorescent lamp according to a sixth exemplary embodiment of the present invention.

FIG. 6B is a cross-sectional view in the longitudinal direction of the double tube fluorescent lamp disclosed in FIG. 6A.

6C is a cross-sectional view illustrating a method in which a double tube fluorescent lamp according to a plurality of sixth embodiments is connected to a power source.

7 is a cross-sectional view showing light emission characteristics according to the diameter of fluorescent lamps.

* Brief description of symbols for the main parts of the drawings *

11: first glass tube 10: second glass tube

20, 21, 22, 23, 40, 50: electrode 30, 31: phosphor

In order to achieve the above object, the double-tube fluorescent lamp proposed in the present invention, the first glass tube, the second glass tube disposed in a direction parallel to the first glass tube inside the first glass tube, the first glass tube and the second glass tube And a space between the glass tubes, the discharge space formed by sealing each other at both ends of the glass tubes, and a fluorescent material applied to an inner wall of the first glass tube and an outer wall of the second glass tube within the discharge space.

Preferably, the thickness of the phosphor coated on the inner wall of the first glass tube is thinner than the phosphor coated on the outer wall of the second glass tube.

Preferably, a metal electrode is formed in a portion of the first glass tube and the second glass tube outside the discharge space, and the electrode is formed from a portion of an outer wall of the first glass tube to a portion of an inner wall of the second glass tube. The electrode formed on the inner wall of the second glass tube is longer than the electrode formed on the outer wall of the second glass tube.

In addition, a portion of the second glass tube other than the electrode may be filled by an insulator.

In addition, the electrode may be formed at both ends of the double tube fluorescent lamp, the electrode may be additionally formed in the central portion of the second glass tube. The discharge space of the portion where the electrode is formed at both ends of the double tube fluorescent lamp may be formed wider than the discharge space of the center portion of the fluorescent lamp. In such a configuration, the diameter of the intermediate portion of the second glass tube can be made larger than the diameter of the portion where the electrodes at both ends of the second glass tube are installed. It is also possible to make the diameter of the intermediate portion of the first glass tube smaller than the diameter of the portion where the electrodes at both ends of the first glass tube are provided.

A metal cap is disposed at both ends of the first glass tube and the second glass tube, whereby a space between the glass tubes is sealed to form the discharge space, and dielectric deposition is formed on a surface where the cap and the discharge space are in contact with each other. An electrode may be formed on the first glass tube and the second glass tube.

In addition, a space between the glass tubes is sealed by metal caps disposed at both ends of the first glass tube and the second glass tube to form the discharge space, and the cap operates as a cold cathode to directly discharge current. Can be.

It is also possible for the length of the double tube fluorescent lamp to have a size similar to the diameter of the first glass tube.

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

FIG. 1A is a perspective view of a double tube fluorescent lamp according to a first embodiment of the present invention, wherein the fluorescent lamp includes a first glass tube 11 and a second glass tube 10 disposed in parallel with the first glass tube inside the first glass tube. The first glass tube 11 and the second glass tube 10 are sealed to form a discharge space, and the sealed portion has an electrode 20 having a structure.

FIG. 1B is a cross-sectional view of the double tube fluorescent lamp according to X-Y of FIG. 1A.

Referring to FIG. 1B, the fluorescent lamp includes a second glass tube 10 having a small diameter disposed inside the first glass tube 11, and both ends of the first and second glass tubes 11 and 10 are mutually sealed. The electrodes 20 are formed at both ends of the first and second glass tubes 11 and 10, and phosphors 31 and 30 are formed on the outer wall of the first glass tube 11 and the inner wall of the second glass tube 10, respectively. Is prepared by applying. As can be seen in Figures 1c and 1d, the fluorescent lamp has a toroidal structure when viewed in cross section.

Therefore, a discharge space is formed between the outer wall of the second glass tube 10 and the inner wall of the first glass tube 11, and like the conventional fluorescent lamp, the discharge space is injected into the discharge space in the electrode 20. When a high voltage is applied, plasma is generated from the discharge gas, and ultraviolet rays generated from the plasma excite the phosphors 30 and 31 to generate light by fluorescence emission.

In particular, in the present invention, the thickness of the phosphor 30 applied to the outer wall of the second glass tube 10 is thicker than the thickness of the phosphor 31 applied to the inner wall of the first glass tube 11. This is to realize the high brightness and high efficiency of the lamp by providing a reflective light emitting method. For reference, the reflective light emission method is known to provide about twice the luminous efficiency than the transmission type light emission method.

In addition, the electrode 20 preferably extends from a portion of the outer wall of the first glass tube 11 to a portion of the inner wall of the second glass tube 10 and is formed on the inner wall of the second glass tube 10. Is formed longer than the electrode formed on the outer wall of the first glass tube (11). This takes into account the non-luminescing area by the electrode 20 itself, which provides uniform discharge and lowers the discharge voltage.

The electrode 23, which is provided at a constant length at a stop portion of the inner wall of the second glass tube 10, is used to uniformly form an annular plasma inside the discharge tube, and to prevent plasma channeling, and the diameter of the glass tube When the length of the lamp is small or the length of the lamp is small, the electrode 23 installed on the inner wall of the second glass tube 10 may be omitted.

1E and 1F are cross-sectional views of a double tube fluorescent lamp in which the discharge space at the electrode portions at both ends of the fluorescent lamp is wider than the discharge space at the center portion of the fluorescent lamp as a modification of the first embodiment. Referring to FIG. 1E, the diameter of the center portion of the second glass tube 10 is made larger than the diameter of the second glass tube 10 at both ends of the fluorescent lamp, and the discharge of the portion where the both ends electrode 20 of the double tube fluorescent lamp is installed. The space portion is formed wider than the discharge space in the middle portion of the double tube fluorescent lamp. Referring to FIG. 1F, the diameter of the middle portion of the first glass tube 11 is made smaller than the diameter of the first glass tube 11 at both ends of the fluorescent lamp, so that the electrodes 20 are installed at both ends of the double tube fluorescent lamp. The discharge space portion is formed wider than the discharge space portion in the center portion of the double tube fluorescent lamp.

The effect of the discharge on the extra-electrode electrode is increased by forming a wide discharge space in the portion where the electrode 20 is installed at both ends of the double-tube fluorescent lamp manufactured as described above.

The electrodes 20 and 23 may be formed by applying a metal material, and may be covered with a separate metal cap after applying the metal material. In addition, an insulator (not shown) may be filled in order to remove the air layer existing in the cavity that is inside the first glass tube 10.

2A is a cross-sectional view of a double tube fluorescent lamp according to a second embodiment of the present invention, and is substantially the same as the fluorescent lamp according to the first embodiment except that the shape of the electrode is different. Therefore, the description of the same parts will be omitted, but will be described with respect to the shape of the electrode.

Referring to FIG. 2A, the double tube fluorescent lamp according to the second embodiment is continuously formed on the inner wall of the first electrode 21 and the second glass tube 10 surrounding the outer wall of the first glass tube 11. An electrode 22 is provided. In particular, the second electrode 22 formed on the inner wall of the second glass tube 10 is substantially formed on the entire inner wall of the second glass tube 10, thereby providing a uniform discharge and lowering the discharge voltage.

2B and 2C are cross-sectional views taken along lines C-C and D-D in FIG. 2A, respectively, and the fluorescent lamp has a donut-shaped structure when viewed in cross section.

3A shows the configuration of the present invention according to the third embodiment, and FIGS. 3B to 3C show a modification of the third embodiment.

Looking at the configuration of the double-tube fluorescent lamp disclosed in Figure 3a, the second glass tube 10 is sealed at both ends is disposed in the interior of the first glass tube 11, both ends of the first glass tube 11, the electrode 21 Sealed to form a discharge space.

3B and 3C are cross-sectional views of a double tube fluorescent lamp having a wide structure of discharge spaces at electrode portions at both ends. Referring to FIG. 3B, the diameter of the middle portion of the second glass tube 10 is greater than the diameter of the second glass tube 10 at both ends of the fluorescent lamp, and the electrode 21 at both ends of the double tube fluorescent lamp is installed. The discharge space portion of is formed wider than the discharge space portion in the middle portion of the double tube fluorescent lamp. Referring to Figure 3c, the diameter of the middle portion of the first glass tube 11 is made smaller than the diameter of both ends of the first glass tube 11, the discharge of the portion where the electrode 21 is installed at both ends of the double tube fluorescent lamp The space portion is formed wider than the discharge space in the center portion of the double tube fluorescent lamp.

The effect of the discharge on the extra-electrode electrode is increased by forming a wide discharge space in the portion where the electrode 21 is installed at both ends of the double-tube fluorescent lamp manufactured as described above.

4A to 4D show a double tube fluorescent lamp according to the fourth embodiment. As a barrier discharge lamp by a dielectric layer, both ends of the first glass tube 11 and the second glass tube 10 disposed inside the first glass tube 11 are sealed to each other by a metal cap 40 so as to have a predetermined discharge. A space is formed and the electrode 20 is formed in the first glass tube 11 around the sealing portions of the first and second glass tubes 11 and 10.

4A is a perspective view of a fluorescent lamp sealed at both ends of a double tube with a metal cap 40, and FIG. 4B is a cross-sectional view in the longitudinal direction of FIG. 4A. In the double tube fluorescent lamp, a cap 40 made of metal for sealing both ends of the double tube is provided, and the cap 40 seals between the first glass tube 11 and the second glass tube 10. At this time, the dielectric 41 is applied to the inside of the cap 40, that is, the inner surface of the fluorescent lamp to be in contact with the discharge space to prevent the discharge space and the cap 40 of the metal material from being directly exposed. At this time, the electrode 20 and the metal cap 40 formed on both outer ends of the second glass tube 11 may be mutually energized from the outside of the glass tube.

The cross section of the fluorescent lamp configured as described above has a structure in which the cross section of the discharge space of the fluorescent lamp is annular (donut type) as shown in FIGS. 4C and 4D.

5A to 5D show a cold cathode lamp in which a current flows directly through a metal encapsulant such as CCFL.

The structure of the double tube fluorescent lamp illustrated in FIG. 5A is similar to that of the double tube fluorescent lamp disclosed in FIG. 4A, that is, both ends of the second glass tube 10 are self-sealed and disposed inside the second glass tube 11. The cap 50 of the metal material is provided at both ends of the double pipe is fastened to both ends of the double pipe as shown in FIG. The sealing portion of the first glass tube 10 is seated and fixed to the inner central portion of the cap 50 of the metal material. An electrode 23 coated with a metal material may be provided on an inner wall of the central portion of the first glass tube 10. The electrode 23 lowers the discharge voltage and prevents plasma channeling. Since the cap 50 itself acts as an electrode, such a configuration constitutes a CCFL.

5C and 5D show cross sections taken along the lines G-G and H-H in FIG. 5B, respectively, in which the cross section of the discharge space of the fluorescent lamp is annular (donut shaped).

6A to 6C show a double tube lamp according to a sixth embodiment.

In the sixth embodiment, a double tube lamp is disclosed having a size in which the length of the fluorescent lamp and the diameter of the first glass tube 11 are substantially similar. Fig. 6A is a perspective view of a double tube similar in length and diameter to the tube, and Fig. 6B is a sectional view in the longitudinal direction. In FIG. 6B, a high voltage is applied to the electrode in the second glass tube 10, and both electrodes outside the first glass tube 11 are preferably grounded. Figure 6c is an example of the use of a long luminaire by connecting a plurality of the double tube fluorescent lamps in the longitudinal direction. Lighting fixtures employing the above connection method can be bent, so that various characters or shapes can be produced.

FIG. 7 is a cross-sectional view illustrating light emission characteristics according to a diameter of a fluorescent lamp. FIG. 6A is a cross-sectional view of a fluorescent lamp having a large diameter of a glass tube. The fluorescent lamp has a large coating area of the fluorescent layer, so that the amount of light emitted is large, but the luminance is not high.

(b) is a case where the diameter of the glass tube is small, and the light emission amount is small but has high luminance. The luminescence properties according to the diameter of the fluorescent lamp as described above are described as follows. In the fluorescent lamp, ultraviolet rays generated from the plasma formed in the discharge tube excite the phosphor to emit light. The density distribution of plasma formed in the discharge tube is higher in the center portion and lower toward the tube wall. The plasma distribution corresponds to the generation distribution of ultraviolet rays, which generally have a short propagation distance. Therefore, when the diameter is large, the light emission luminance is small since the fluorescent light is emitted by the low light ultraviolet light at the edge of the plasma center, and when the diameter is small, the light emission light is emitted by the high light ultraviolet light at the plasma center.

(c) is sectional drawing of the double tube fluorescent lamp which concerns on this invention. A small diameter glass tube is disposed inside a large diameter glass tube, and an annular plasma is formed between the inner tube and the outer tube. Phosphors are respectively applied to the inner tube and the outer tube of the discharge space.

Ultraviolet rays generated from the circular plasma cause the phosphor in the inner tube and the phosphor in the exterior to emit light. Therefore, high luminance is obtained by the high intensity ultraviolet rays generated from the toroidal plasma, and at the same time, high luminance and large light amount are realized from the double fluorescent layer.

The driving method of the double tube of the present invention can be used by applying a high frequency of MHz to the double tube as well as a low frequency of several tens Hz to several hundred kHz.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to the present invention as described above, by providing a double tube structure, the coating area of the phosphor is expanded, and as a result, the amount of light emitted from the lamp can be greatly increased. In addition, by providing a reflective light emitting method has the advantage that the high brightness and high efficiency of the lamp can be realized. Therefore, the fluorescent lamp according to the present invention is a light source of long life, high brightness, high capacity, and can be used as a light source for general lighting, a large screen LCD backlight, a copier light source, a billboard light source, and the like.

Claims (13)

A first glass tube; A second glass tube disposed in a direction parallel to the first glass tube inside the first glass tube; A discharge space formed by sealing a space between the first glass tube and the second glass tube at both ends of the glass tubes; A fluorescent material applied to an inner wall of the first glass tube and an outer wall of the second glass tube in the discharge space; And A double tube fluorescent lamp comprising a metal electrode formed on the first glass tube and the second glass tube. The double tube fluorescent lamp of claim 1, wherein a thickness of the phosphor applied to the inner wall of the first glass tube is thinner than a thickness of the phosphor applied to the outer wall of the second glass tube. The electrode of claim 1, wherein the electrode is formed from a portion of an outer wall of the first glass tube to a portion of an inner wall of the second glass tube, and an electrode formed on an inner wall of the second glass tube is formed on an outer wall of the second glass tube. Double tube fluorescent lamp, characterized in that longer. The double tube fluorescent lamp of claim 1, wherein a portion of the second glass tube other than the electrode is filled by an insulator. The double tube fluorescent lamp of claim 1, wherein the electrodes are formed at both ends of the double tube fluorescent lamp. 6. The double tube fluorescent lamp of claim 5, wherein a discharge space in a portion where electrodes are formed at both ends of the double tube fluorescent lamp is wider than a discharge space in a center portion of the fluorescent lamp. The double tube fluorescent lamp according to claim 6, wherein the diameter of the middle portion of the second glass tube is larger than the diameter of the portion where the electrodes at both ends of the second glass tube are installed. The double tube fluorescent lamp according to claim 6, wherein the diameter of the intermediate portion of the first glass tube is smaller than the diameter of the portion where the electrodes at both ends of the first glass tube are installed. The space between the glass tubes is sealed by metal caps disposed at both ends of the first glass tube and the second glass tube to form the discharge space, and the cap and the discharge space are in contact with each other. A dielectric tube is applied, and a double tube fluorescent lamp, characterized in that an electrode is formed on the first glass tube and the second glass tube. The space between the glass tubes is sealed by metal caps disposed at both ends of the first glass tube and the second glass tube to form the discharge space, and the cap operates as a cold cathode to discharge current. Double tube fluorescent lamp characterized in that flowing directly. The double tube fluorescent lamp of claim 1, wherein the length of the glass tube is about the same size as the diameter of the first glass tube. 6. The double tube fluorescent lamp of claim 5, wherein an electrode is additionally formed on an inner wall of the center portion of the second glass tube. The double tube fluorescent lamp of claim 1, wherein both ends of the second glass tube are sealed.