JP5259985B2 - Fluorescent tube - Google Patents

Description

  The present invention relates to a cold cathode fluorescent lamp, a fluorescent display tube, and other fluorescent light emitting tubes. More specifically, an electron emitter (cold cathode), an anode with a phosphor, Are arranged so as to face each other, electrons are emitted from the electron emitter toward the anode, and the emitted electrons collide with a phosphor arranged on the front surface of the anode to excite and emit the phosphor.

  Some fluorescent tubes are used as display devices by making the container into a flat panel shape (Patent Document 1).

  In such a display device, white light emission is required, for example, for use in a backlight. White light emission includes, for example, a phosphor film in which a phosphor that emits yellow to red light and a phosphor such as ZnO: Zn phosphor that emits green to blue light are formed (see Patent Document 2). . However, in this phosphor film, as described in Patent Document 2, although the lifetime is stabilized by the ZnO: Zn phosphor, the desired luminance cannot be obtained. In addition, there is a problem that the luminance depends on the voltage depending on the type of the phosphor, and a color shift, which is a phenomenon in which the emission color changes due to the change of the driving voltage, occurs.

  An anode having ZnO: Zn phosphors as light emitting dots is arranged on the rear (back) side of the envelope evacuated to a high vacuum state, and an RGB color filter is arranged on the front (front) side. There has been proposed a display device in which a filamentary cathode that emits electrons is disposed between RGB color filters (see Patent Document 3). In this display device, instead of arranging an RGB phosphor on the anode, a ZnO: Zn phosphor having a short afterglow is arranged on the anode, and color graphic display is performed using a color filter of each color. However, this display device is a multicolor display and is not a display device that emits white light.

In addition, the fluorescent tube must be maintained in a vacuum, but it may be caused by trace residual moisture or trace residual gas (hereinafter referred to as trace residual gas) present in the manufacturing process or trace residual gas generated during operation. The degree of vacuum is lowered, the electron emitter disposed inside is deteriorated, the luminance is lowered, and the life characteristic is low. For this reason, it is conceivable to arrange a getter having a slight residual gas adsorptivity inside the fluorescent light emitting tube, but the fluorescent light emitting tube is made thinner and ultra-small to make it difficult to secure a space for arranging the getter. That is, the getter has a diameter of about several millimeters and requires a space for avoiding contact with other members such as electrodes, and is disposed at a position that does not hinder the light emitting display, and if it is separated from the phosphor by a predetermined distance, Sometimes adsorption of trace residual gas generated from the body is insufficient. In addition, a non-evaporable getter that is disposed by a printing method, a sputtering method or the like and adsorbs a trace amount of residual gas generated from a phosphor is activated by resistance heating or the like by providing a wiring for activation. There is a need for a process or activation at high temperatures to improve the getter effect. In addition, the fluorescent arc tube manufacturing process includes a high-temperature sealing process, a vacuum sealing exhaust process, and the like, and the phosphor is affected by various environments, and its surface is easily contaminated and easily deteriorated. Furthermore, there is a problem that the light emission characteristics become unstable due to the influence of a trace amount of moisture and other trace residual gases in the fluorescent display tube (see Patent Document 4).
JP 2004-134173 A JP 2006-140001 A JP 09-305127 A JP 2006-313675 A

  The problem to be solved by the present invention is to provide a fluorescent light emitting tube having a stable brightness level and a long life by diffusing the excitation light emission of the phosphor to enable uniform light emission and imparting a certain getter property of a trace residual gas in the tube. That is.

A fluorescent light emitting tube according to the present invention provides a phosphor containing Zn oxide on the inner surface of a light-transmitting light emitting portion provided in a container evacuated to a vacuum, and provides a light diffusibility and a getter effect to the vacuum inside the container. A white light emitting phosphor is provided in the container, and an anode with a white light-emitting phosphor and an electron emitter that emits electrons when an electric field is applied between the anode and the container are arranged opposite to each other. An anode with a phosphor is disposed behind the light diffusion / getter portion in the container, the electron emitter is disposed between the light diffusion / getter portion and the anode, and the anode is disposed behind the anode with respect to the light emitting portion. A light reflecting portion for reflecting the excitation light emission of the white light emitting phosphor toward the light emitting portion is disposed, the electron emitter is formed with an electron emitting film on the surface of the conducting wire, and the electron emitting film is formed on the surface of the conducting wire. Of the semicircular area facing the anode Formed, ZnO and the light diffusing / getter unit: and is characterized in that is constituted by Zn phosphor.

Examples of the phosphor containing an oxide of Zn include ZnO: Zn phosphor, ZnGa ₂ O ₄ phosphor, and ZnGa ₂ O ₄ : Mn phosphor. In particular, among these oxide phosphors, a ZnO: Zn phosphor can be preferably selected.

  The light diffusion / getter portion does not exclude the case where a substance other than a phosphor containing Zn oxide is included, and the light diffusion / getter portion can be included in the present invention if it has a light diffusion property and a getter function.

  The light diffusion / getter portion is preferably composed of a ZnO: Zn phosphor, but is not limited to being composed entirely of a ZnO: Zn phosphor or other oxide phosphor.

  The fluorescent tube is not particularly limited in its name and shape, and includes, for example, a cold cathode fluorescent lamp, a fluorescent display tube, and the like. The container shape includes a tube type and a flat panel type. Examples of the container include a glass container, a glass tube, and a flat panel type glass container.

  When the whole container is comprised with the glass tube which consists of glass materials, the whole glass tube can comprise the light-projection part. Further, if the container has a flat panel shape including a front panel and a rear panel, the whole or a part of the front panel can constitute the light emitting portion.

  The name and shape of the electron emitter are not particularly limited as long as the electron emitter emits electrons by field emission. For example, the electron emitter includes a carbon film having fine protrusions formed on the conductor surface. Examples of the carbon film include carbon nanotubes, carbon nanowalls, and acicular carbon films.

  The material of the white light emitting phosphor is not particularly limited. White is not narrowly defined, and is not limited to lightness and darkness, and may include some color mixture with other colors.

  According to the present invention, since the light diffusing / getter portion having the adsorptivity of a trace amount of residual gas is provided on the inner surface of the light emitting portion, it becomes possible to suppress the deterioration of the electron emitter and to maintain the electron emission performance of the electron emitter for a long period of time. At the same time, the brightness level due to the light emission of the phosphor due to the electron emission from the electron emitter is stabilized, and the life characteristics are improved.

  Further, since the light diffusion / getter portion is provided on the inner surface of the light emitting portion, the light emission property makes it possible to diffuse excitation light emission from the white light emitting phosphor, and uniform white light emission is possible.

  The rear in the container is, for example, the rear panel side in the flat panel type, and the center side in the tube type.

  When the light reflecting portion is disposed on the anode back portion, it is preferable because the luminance can be improved by the reflected light from the light reflecting portion.

In a further preferred embodiment of the present invention, the white light emitting phosphor is a mixture of RGB phosphor and ZnO: Zn phosphor, or a laminate of RGB phosphor and ZnO: Zn phosphor in layers. It is. In the case of this aspect, it is preferable that high luminance and long life can be achieved by the high luminance excitation light emission characteristics of the RGB phosphor, the conductivity of the ZnO: Zn phosphor and the adsorptivity of a trace residual gas. Note that RGB phosphors and ZnO: Zn phosphors may be mixed, or both phosphors may be stacked as separate phosphor layers, as long as they can emit white light. In the case of the above stacking, when a low-speed electron beam is used in a fluorescent light emitting tube such as a fluorescent display tube, the depth of arrival inside the phosphor due to electron collision is shallow, so the film thickness of the ZnO: Zn phosphor is controlled. It is preferable to be able to reach the RGB phosphor.

  ADVANTAGE OF THE INVENTION According to this invention, the brightness | luminance level is stabilized, a lifetime characteristic is favorable, and the fluorescent tube which can emit white light uniformly can be provided.

  Hereinafter, a fluorescent light emitting tube according to an embodiment of the present invention will be described with reference to the accompanying drawings. 1 is a cross-sectional side view of the fluorescent light emitting tube, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is a schematic view of the main part of the fluorescent light emitting tube for explaining the light emission principle of the fluorescent light emitting tube of FIG. FIG. 4 is a diagram comparing the life characteristics of a conventional fluorescent light emitting tube and the fluorescent light emitting tube of the embodiment.

  Referring to these drawings, reference numeral 10 denotes a fluorescent light emitting tube, and this fluorescent light emitting tube 10 has a thin flat panel type container shape whose inside is evacuated to vacuum, and includes a front panel 12, a rear panel 14, It consists of a side panel. The side panel is omitted for convenience of illustration. The front panel 12 is made of a light transmissive glass material. In this embodiment, the entire surface of the front panel 12 constitutes a light transmitting portion. A ZnO: Zn phosphor is provided on the inner surface of the front panel 12 as a light diffusion / getter unit 16.

  A ZnO: Zn phosphor has a high residual rate of luminance after continuous light emission and contributes to luminance stabilization, and a ZnO: Zn phosphor alone or a mixed phosphor with another phosphor is adopted as an excitation light emission source. However, the ZnO: Zn phosphor is a blue or green emitting phosphor, and needs to be mixed with other phosphors to emit white light. In the embodiment, such a ZnO: Zn phosphor is not used as an excitation emission source, but an RGB phosphor or a red emission phosphor is used as an excitation emission source. In this case, it is necessary to arrange the getter in the fluorescent light emitting tube 10 in order to stabilize the luminance of the excitation light emitting source. However, when the fluorescent light emitting tube 10 becomes thin or ultra-small, an ordinary getter is arranged inside. It is difficult to do. Therefore, in the embodiment, a thin layer of ZnO: Zn phosphor is arranged as the light diffusion / getter unit 16.

  This ZnO: Zn phosphor is called a self-activated zinc oxide phosphor and is known as a phosphor exhibiting blue or green light emission excited by an electron beam. Since this phosphor has a low light emission threshold and a long life, it is frequently used for a fluorescent display tube that emits light by exciting the phosphor with a low-speed electron beam. In the embodiment, the ZnO: Zn phosphor is not used to emit light, but is used as a functional phosphor assumed from experimental results as a light diffusion / getter unit 16 for imparting light diffusibility and getter effect. .

  As a result of the fact that the ZnO: Zn phosphor was appropriately selected from experiments and composed of several layers of phosphor particles, the luminance level was stabilized over a long period of time and the uniform light emission property was maintained high. While the ZnO: Zn phosphor used as the diffusion / getter unit 16 can diffuse the light passing from one side to the other side, the fluorescent arc tube 10 includes a trace amount of moisture and a trace amount contained in the manufacturing process. It can be considered that gas or a minute amount of gas generated during operation is adsorbed to maintain the degree of vacuum in the fluorescent light emitting tube 10 to prevent the electron emitter 18 from being deteriorated.

  The phosphor particles constituting the ZnO: Zn phosphor have an average particle diameter in the range of 1 to 20 μm, particularly preferably around 5 μm. The reason why the phosphor particles are limited to the above range is that the light diffusibility decreases when the particle size is smaller than 1 μm, whereas the getter effect decreases when the particle size is larger than 20 μm.

  Forming the phosphor constituting the light diffusion / getter unit 16 on the inner surface of the front panel 12 may be performed by a known technique. For example, a phosphor paste in which a ZnO: Zn phosphor and an organic solvent binder are mixed is applied to the inner surface of the front panel 12, and the organic solvent is evaporated by heating and drying, whereby the light diffusion / getter unit 16 is formed on the inner surface of the front panel 12. It is possible to form.

  A plurality of electron emitters 18 are arranged between the front panel 12 and the rear panel 14. A plurality of the electron emitters 18 are arranged in parallel with each other in a wire shape and at equal intervals in the circumferential direction. The electron emitter 18 is configured by forming an electron emission film 18b on the surface of a conducting wire 18a. The electron emission film 18b is made of a carbon film having fine projections in the order of nm, such as carbon nanotubes, carbon nanowalls, and acicular carbon films, that emit electrons by field emission. A description of the method of forming the electron emission film 18b on the surface of the conductive wire 18a is omitted, but any method may be used. The electron emission film 18b may be formed on the entire outer peripheral surface of the conducting wire 18a as shown enlarged in the circle P1, but as shown in the enlarged view in the circle P2, the anode 18a It is formed only in the semicircular region facing the 22 side. By forming the electron emission film 18b in the semicircular region as described above with respect to the conductive wire 18a, the electrons emitted from the electron emission film 18b are prevented from irradiating the light diffusion / getter portion 16 made of ZnO: Zn phosphor. In addition, the power consumption can be reduced.

On the inner surface of the rear panel 14, a light reflecting portion 20, an anode 22, and a white light emitting phosphor 24 are laminated in this order. The white light emitting phosphor 24 is composed of an RGB phosphor 24a in which red (R), green (G), and blue (B) phosphors are kneaded as shown in an enlarged view in a circle P3. As shown enlarged in the circle P4, the ZnO: Zn phosphor 24b may be mixed with the RGB phosphor 24a. In this case, the mixing ratio and the like are adjusted so that the mixed phosphor is white. The ZnO: Zn phosphor 24b can be mixed instead of In ₂ O _3, for example. In ₂ O ₃ is effective in preventing charge-up by imparting conductivity to the white light-emitting phosphor 24, but the cost is high, while the ZnO: Zn phosphor has low resistance and imparts conductivity to prevent charge-up. Can be done at the same time. The white light-emitting phosphor 24 uses a red light-emitting phosphor instead of the RGB phosphor, and the red light-emitting phosphor may be mixed at a mixing ratio so that ZnO: Zn phosphor emits white light. Good. Longevity of the white light emitting phosphor 24 can be achieved by mixing the ZnO: Zn phosphor 24b with the RGB phosphor or the red light emitting phosphor. Further, by adopting the RGB phosphor 24a, it is possible to achieve high luminance light emission.

In the fluorescent light emitting tube 10 of the embodiment having the above configuration, as shown in FIG. 3, electrons are transferred from the electron emission film 18 b of the electron emitter 18 by applying an electric field between the electron emitter 18 and the anode 22. As shown by 26, the electrons are emitted toward the anode 22, and the electrons collide with the white light-emitting phosphor 24, thereby causing the white light-emitting phosphor 24 to emit light as shown by an arrow 28 and pass through the front panel 12. Then, as indicated by an arrow 29 , light emission is emitted out of the fluorescent light emitting tube 10. In the above case, the light emission of the white light emitting phosphor 24 is present not only on the front panel 12 side but also on the rear panel 14 side, and the light emission toward the rear panel 14 side is reflected by the light reflecting portion 20 as indicated by an arrow 31 . This reflection increases the amount of emitted light emitted from the front panel 12. In addition, the light diffusion of the arrow 29 in the drawing is simply shown for understanding, and the light diffusion direction is considered to be more complicated.

  In the above description, the light emission indicated by the arrow 28 from the white light emitting phosphor 24 is diffused by the light diffusion / getter unit 16 as indicated by the arrow 30, resulting in uniform light emission from the front of the front panel 12. On the other hand, the light emission indicated by the arrow 28 from the white light emitting phosphor 24 is adsorbed by the light diffusing / getter unit 16 with a small amount of residual gas, so that the life characteristics of the fluorescent light emitting tube 10 are improved.

The life characteristics of the conventional fluorescent light emitting tube (not shown) with reference to FIG. 4 and the fluorescent light emitting tube 10 of the embodiment will be compared. In FIG. 4, the horizontal axis represents the elapsed time (hr) of use of the fluorescent tube, and the vertical axis represents the luminance (cd / m ² ). S1 represents the life characteristic line of the embodiment, and S2 represents the life characteristic line of the conventional fluorescent tube.

  A conventional fluorescent tube has an anode with a white light emitting phosphor made of RGB phosphor on the inner surface of a front panel and an electron emitter on the inner surface side of the rear panel, and no getter is disposed.

  In both the prior art and the embodiment, the actual measurement time of the life characteristics is several hundred hours. As is apparent from the comparison of the two life characteristic lines S1 and S2 within the actual measurement time, the fluorescent light emitting tube according to the embodiment is superior in life characteristic to that of the prior art. That is, unlike the conventional example, in the embodiment, the luminance does not decrease from the stabilized initial luminance even after the operation time has passed for several hundred hours from the start of the display operation of the fluorescent tube, and the luminance is It is stable at almost constant luminance level.

  The above-mentioned constant transition of the luminance level is caused by using the ZnO: Zn phosphor as the material of the light diffusion / getter portion 16 even when a phosphor not containing the ZnO: Zn phosphor is used for the anode. This is thought to be due to the adsorption of trace residual gas. In the embodiment, in addition to the adsorption action of the ZnO: Zn phosphor, the light diffusing action is used at the same time, thereby enabling uniform light emission. In particular, it is considered that when a normal trace residual gas adsorbing material is disposed on the inner surface of the front panel 12, it is difficult to obtain light diffusion even if the trace residual gas is adsorbed, but rather causes a decrease in luminance due to light absorption. On the other hand, in the embodiment, since the ZnO: Zn phosphor is used as the material of the light diffusion / getter unit 16, the life characteristics are improved and uniform light emission is achieved simultaneously by the adsorption of a trace amount of residual gas.

  In addition to the above effects, in the present embodiment, since the white light emitting phosphor 24 is arranged on the rear panel 14 side instead of the front panel 12 side, the fluorescent light emission in which the white light emitting phosphor is arranged on the inner surface of the front panel 12 is provided. Compared with a tube, light absorption by the white light-emitting phosphor 24 is eliminated, the white light-emitting phosphor 24 can be densely provided, and the amount of excitation light emission can be increased more than before. In particular, in a fluorescent tube, when a phosphor is excited to emit light by irradiating it with a slow electron beam, the slow electron beam penetrates only from the surface to a few angstroms. (See JP 2006-313675). In the embodiment, by providing the white light-emitting phosphor densely, the surface state of the white light-emitting phosphor can be adjusted, and a film-forming state with excellent light emission efficiency can be obtained.

  Further, as described above, since the light reflecting portion 20 is disposed on the back portion of the anode 22, not only the light emitted from the white light emitting phosphor 24 but also the light emitted from the front panel 12 to the front side is emitted. Reflected light from the reflecting portion 20 is also added, and the amount of emitted light can be increased and increased compared to the conventional case.

  Furthermore, since the electron emission film 18b of the electron emitter 18 is provided on the conducting wire 18a for the semicircular direction toward the anode 22, the white light emitting phosphor 24 can efficiently emit electrons from the electron emission film 18b. In order to obtain the same amount of emitted light, the power consumption of the fluorescent tube 10 can be reduced by at least half compared to the case where the electron emission film 18b is provided on the entire circumference of the conductive wire 18a. Become.

  A fluorescent tube according to another embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a side sectional view of the fluorescent light emitting tube, FIG. 6 is a sectional view taken along line BB of FIG. 5, and FIG.

  With reference to these drawings, the fluorescent light emitting tube 30 according to this embodiment has a double tube configuration of an outer tube 32 and an inner tube 34, and the inner surface of the outer tube 32 is made of ZnO: Zn phosphor. A light diffusion / getter unit 36 is provided, and a plurality of electron emitters 38 having a wire shape with a required wire diameter are disposed between the outer tube 32 and the inner tube 34. The inner tube 34 may be hollow or solid. On the outer surface of the inner tube 34, a light reflecting portion 40 that is electrically insulating and has a light reflecting action, an anode 42 as a counter electrode of the electron emitter 38, and an RGB phosphor as a white light emitting phosphor of low-energy electron beam irradiation excitation emission type 44 are stacked in this order.

  The plurality of electron emitters 38 are arranged in the form of wires extending around the inner tube 34 at equal intervals in the circumferential direction and parallel to each other in the tube axis direction. These electron emitters 38 may be provided with an electron emission film 38b in the entire peripheral region of the conducting wire 38a. However, in the embodiment, in order to improve the effect of electron emission, the side semicircle facing the anode 42 instead of the entire peripheral region. An electron emission film 38b is provided in the peripheral region.

  Although a plurality of the electron emitters 38 are arranged in parallel, one wire-like electron emitter may be arranged while spiraling around the anode side in the tube axis direction. In this case, a light-transmitting insulating intermediate tube may be disposed between the outer tube 32 and the inner tube 34, and an electron emitter may be spirally disposed on the outer peripheral surface of the intermediate tube. Alternatively, the electron emitter may be arranged in a ring around the anode side.

  Referring to FIG. 7, in the fluorescent light emitting tube 30 of the above embodiment, as with the fluorescent light emitting tube 10, the electric field between the electron emitter 38 and the anode 42 is applied from the electron emission film 38 b of the electron emitter 38. Electrons are emitted toward the anode 42, and the electrons collide with the RGB phosphor 44, whereby the RGB phosphor 44 is excited and emitted, passes through the outer tube 32, and is emitted and emitted out of the fluorescent tube 30. . In the above case, light emitted from the RGB phosphor 44 toward the anode 42 is reflected by the light reflecting portion 40, and the amount of light emitted from the fluorescent light emitting tube 30 increases.

In the case of the fluorescent light emitting tube 30 of this embodiment, as in the case of the fluorescent light emitting tube 10, the luminance changes at a substantially constant luminance level by the light diffusion / getter unit 36 made of ZnO: Zn phosphor on the inner surface of the outer tube 32. As a result, the lifetime characteristics are improved, and uniform light emission is possible by the light diffusing action.

  Further, since the RGB phosphors 44 are arranged not on the inner surface side of the outer tube 32 but on the inner tube 34 side, the RGB phosphors 44 can be densely provided, and the amount of excitation light emission can be increased more than before. It becomes like this.

  Furthermore, as described above, since the light reflecting portion 40 is disposed on the back of the anode 42, the light reflection amount of the light reflecting portion 40 can increase the amount of emitted light more than before. Furthermore, since the electron emission film 38b of the electron emitter 38 is provided for the semicircular portion toward the anode 42 side, the power consumption of the fluorescent light emitting tube 30 can be reduced to at least half as in the case of the fluorescent light emitting tube 10. become able to.

  In the case where the fluorescent light emitting tube is of a flat panel type, as a phosphor on the anode surface side, a RGBO phosphor may be mixed with a ZnO: Zn phosphor to improve its life characteristics.

  The fluorescent light-emitting tube of the embodiment can take various forms depending on the use of various light sources including the backlight for liquid crystal display devices. The shape is not limited.

  The particle size of the phosphor particles constituting the ZnO: Zn phosphor used for the light diffusion / getter portions 16 and 36 is preferably about several μm and preferably about several layers. The light diffusing / getter portions 16 and 36 may be composed of only phosphor particles, but may be composed of several layers in a translucent resin in which the phosphor particles are dispersed.

  The light diffusing / getter portions 16 and 36 may be attached to the front panel 12 and the inner surface of the outer tube 32 as a sheet, or may be formed by a slurry coating method, a screen printing method, an electric perturbation method, a sedimentation method, or the like. Good.

  The present invention is not limited to the above-described embodiment, and includes various changes or modifications within the scope described in the claims.

FIG. 1 is a side sectional view of a fluorescent light emitting tube according to an embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a schematic enlarged view showing a main part of the fluorescent light emitting tube for explaining the light emission principle of the fluorescent light emitting tube of FIG. FIG. 4 is a diagram for comparing the life characteristics of the fluorescent light emitting tube according to the prior art and the embodiment. FIG. 5 is a side sectional view of a fluorescent light emitting tube according to another embodiment. 6 is a cross-sectional view taken along line BB in FIG. FIG. 7 is an enlarged view of a main part for explaining the operation of the fluorescent light emitting tube of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fluorescent light-emitting tube 12 Front panel 14 Rear panel 16 Light diffusion / getter part 18 Electron emitter 20 Light reflection part 22 Anode 24 White light-emitting phosphor

Claims (2)

A light diffusing / getter unit that maintains a vacuum in the container by providing a phosphor containing Zn oxide on the inner surface of the light transmitting unit provided in the container evacuated to a vacuum, providing light diffusibility and a getter effect And providing an anode with a white light emitting phosphor in the container and an electron emitter that emits an electron by applying an electric field between the anode,
The white light emitting phosphor-attached anode is disposed behind the light diffusion / getter portion in the container, and the electron emitter is disposed between the light diffusion / getter portion and the anode,
A light reflecting portion that reflects the excitation light emission of the white light emitting phosphor toward the light emitting portion behind the anode with respect to the light emitting portion,
The electron emitter is formed with an electron emission film on the surface of the conductive wire, and the electron emission film is formed in a semicircular region facing the anode of the surface of the conductive wire ,
A fluorescent light emitting tube characterized in that the light diffusion / getter portion is composed of a ZnO: Zn phosphor .   2. The white light emitting phosphor as described above, wherein RGB phosphor mixed with ZnO: Zn phosphor, or RGB phosphor and ZnO: Zn phosphor laminated in layers are used. The fluorescent light-emitting tube as described.

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