JP2001351579A - Fluorescent lamps and lighting devices - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp and a lighting system using the fluorescent lamp having an excellent characteristic drop of light output. SOLUTION: This fluorescent lamp is provided with an elongate light transmitting airtight vessel 1; a discharge medium sealed in the light transmitting airtight vessel 1; at least a pair of electrodes 4, 5 disposed to cause discharge; and a phosphor layer 3 disposed on the inner surface side of the light transmitting airtight vessel to radiate white light using a luminescent phosphor of three or more wavelength including at least RGB, wherein visible light drops down to 1/10 of steady radiation time within 2.0×10-3 seconds after shutting out ultraviolet irradiation. The phosphor is formed using at least one kind of Y2O2S: Eu and YVO4:Eu for red luminescence, SrAl2O4:Eu for green luminescence and at least one kind of BaMgAl10O17:Eu and (Sr, Ca, Ba)10(PO4)3Cl2:Eu for blue luminescence. This fluorescent lamp is ideal for a back light or the like of a liquid crystal display device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluorescent lamp and a lighting device using the same.

[0002]

2. Description of the Related Art In a fluorescent lamp, generally, ultraviolet rays are generated by the discharge of mercury vapor or a rare gas, and the generated ultraviolet rays irradiate the phosphor layer to excite the phosphor contained in the phosphor layer. Emit visible light. Then, the visible light radiated into the fluorescent lamp is transmitted through the translucent airtight container, led out to the outside, and used for illumination and the like.

[0003] As one form of utilization of a fluorescent lamp, a fluorescent lamp having a relatively small diameter and a long and thin translucent airtight container is often used for a backlight of a liquid crystal display device. In such a fluorescent lamp, a three-wavelength light emitting phosphor is used.

By the way, as a method of clarifying moving image display in a liquid crystal display device, in order to compensate for poor responsiveness of liquid crystal, when a fluorescent lamp is blinked for each field of a moving image, the response to the blinking of the fluorescent lamp is required. That is, when a high blinking characteristic is required, the attenuation characteristic of the light output of the phosphor becomes a problem.

[0005]

Conventionally, generally used three-wavelength light emitting phosphors have an attenuation characteristic of light output of 2.5 × 10 ⁻³ seconds or more. It has been found that high response cannot be obtained with such an optical output attenuation characteristic. In the present invention, the term “light output attenuation characteristic” means that the light output is attenuated to 1/10 of the steady state after the ultraviolet irradiation to the phosphor is stopped by stopping the supply of the lamp power to the fluorescent lamp. The time until. Then, the present inventor investigated the attenuation characteristics of the light output of the phosphor, and as a result, Y, which is generally used as a phosphor emitting red light, was used.
_It has been found that the reason is that the light output attenuation characteristics of LaO ₄ : Ce and Tb, which are generally used as phosphors for ₂ O ₃ : Eu and green light emission, are inferior. On the other hand, a blue-emitting phosphor such as BaMgAl ₁₀ O
₁₇ : Eu and the like have good optical output attenuation characteristics.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fluorescent lamp having a good light output attenuation characteristic and a lighting device using the same.

[0007]

A fluorescent lamp according to the present invention comprises an elongated light-transmitting airtight container; a discharge medium sealed in the light-transmitting airtight container to generate ultraviolet rays by electric discharge; At least one pair of electrodes disposed so as to generate a discharge in an airtight container; and a light emitting type of at least three wavelengths including RGB and 2.0 × 10 after blocking ultraviolet irradiation.
A phosphor layer which emits white light and is disposed on the inner surface side of the light-tight hermetic container using a phosphor whose visible light emission is attenuated to 1/10 of the steady irradiation within ³ seconds. It is characterized by having.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

<About the Translucent Airtight Container> The translucent airtight container is most preferably manufactured by sealing both ends of a glass bulb or sealing an opening formed at one end of a T-shaped glass bulb. Although it is preferable because it is easy and the cost is low, it may be formed of a translucent ceramic if necessary. Note that as the glass, soft glass, semi-hard glass, hard glass, quartz glass, or the like can be appropriately selected and used. “Translucent” of a light-transmitting airtight container does not require that the entire light-transmitting airtight container be light-transmitting, and at least visible light radiated from the phosphor layer upon discharge. It is only necessary that the portion that attempts to lead out to the outside be transparent to the light. In addition, that the light-transmitting airtight container is elongated means that the light-transmitting airtight container has a length that is at least twice the outer diameter of the discharge container.

Further, the light-transmitting airtight container may be either a straight tube or a curved tube. For example, U-shaped
Various shapes such as a U-shape, a double U-shape, an L-shape, a U-shape, an annular shape and a semi-annular shape can be adopted.

Further, in the present invention, the translucent airtight container may have a flat cross section, a quadrangle, a triangle, or the like.

<Regarding the Discharge Medium> The discharge medium is preferably used in the present invention because it is composed mainly of a rare gas, whereby the luminous flux rising characteristics are improved. As the rare gas, xenon, neon, argon, krypton, and the like can be used alone or in any combination. In the case where the fluorescent lamp performs a dielectric barrier discharge, a rare gas halide such as KrF or ArCl or a simple halogen may be added in addition to the rare gas. As the halogen, iodine, bromine, and chlorine can be used. If the element exists as a vapor in the range of several hundreds to about 1 MPa, discharge is possible.

However, when the fluorescent lamp performs arc discharge, a discharge medium composed of mercury and a rare gas can be used instead of a discharge medium mainly composed of a rare gas, if necessary.

<Regarding Electrodes> If at least one pair of the electrodes is arranged so as to generate a discharge through the discharge medium inside the light-transmitting airtight container, the electrodes inside and outside the light-transmitting airtight container are provided. Any of them may be used.

That is, when the fluorescent lamp is configured to perform arc discharge, at least a pair of electrodes can be separated and sealed inside the translucent airtight container.

On the other hand, when the fluorescent lamp is configured to perform dielectric barrier discharge, the electrodes can be provided as follows. One or a plurality of electrodes constituting one of the electrodes forming at least a pair can be sealed inside the translucent airtight container, and the other electrode can be disposed almost in close contact with the outer surface of the translucent airtight container. . As such a configuration,
For example, as a first mode, a pair of internal electrodes are sealed at both ends inside a light-transmitting airtight container, and these internal electrodes are connected to one pole of a lighting circuit to form one electrode, thereby forming a light-transmitting airtight container. One external electrode can be provided on the outer surface of the hermetic container and connected to the other electrode of the lighting circuit to serve as the other electrode. As a second aspect, the pair of internal electrodes may be connected to one pole of two lighting circuits, and the external electrodes may be commonly connected to the other pole of each lighting power supply. Third
As one aspect, one or more internal electrodes are sealed at one or both ends inside the light-transmitting airtight container, and a plurality of external electrodes are arranged on the outer surface of the light-transmitting airtight container so as to be spaced apart from each other, Can be commonly connected to one pole of a plurality of lighting circuits, and each external electrode can be individually connected to the other pole of each lighting circuit.

Further, at least one pair of external electrodes can be arranged on the outer surface of the light-transmitting airtight container so as to be spaced apart and opposed to each other.
For example, as a first embodiment, a pair of external electrodes of substantially the same size can be disposed facing each other. As a second aspect, one external electrode is provided along the longitudinal direction of the light-transmitting hermetic container, and the other external electrode facing the external electrode is provided as a plurality of external electrodes. , And the other plurality of external electrodes can be individually connected to the other poles of the plurality of lighting circuits.

Next, the electrode sealed in the light-transmitting airtight container can be formed in a short form regardless of whether it is an arc discharge or a dielectric barrier discharge. Further, in the case of the dielectric barrier discharge, the dielectric barrier discharge may have a long form extending along the longitudinal direction of the light-transmitting airtight container. In any of the above-mentioned embodiments, a normal cold cathode type or a hot cathode type can be used.

Furthermore, in the case of an internal electrode sealed inside a light-transmitting airtight container, a known method such as a flare seal, bead seal, pinch seal, etc. can be used to seal the internal electrode at an end or an intermediate portion of the light-transmitting airtight container. Various sealing means can be appropriately selected and used.

On the other hand, in the case of an external electrode provided outside the light-transmitting hermetic container, the external electrode is made of a conductive material such as a coil, a mesh structure, a transparent conductive film or a metal foil, and is formed of a conductive material. It can be configured to be disposed substantially in contact with the outer surface. It should be noted that the phrase “the external electrode is disposed substantially in contact with the outer surface of the light-transmitting airtight container” preferably means that the entire external electrode is in contact with the outer surface of the surface of the light-transmitting airtight container. However, this is not an essential requirement, and generally means that the external electrode only needs to be in contact with the outer surface of the light-transmitting airtight container. Further, the external electrode may have a size such that at least a part thereof extends to a position separated from the internal electrode in the longitudinal direction, that is, the axial direction of the light-transmitting airtight container. And in the outer peripheral direction of the translucent airtight container, it can be disposed within an angle range forming the entire periphery or a part of the outer periphery. Furthermore, when the external electrode is composed of a coil, a mesh structure, and a transparent conductive film, these components transmit light through the external electrode and are guided to the outside. Can be arranged. On the other hand, when the external electrode is made of a metal foil, the metal foil is not substantially translucent, so that the angle forming a part of the outer periphery of the translucent airtight container so as to leave the light guide opening. Be arranged within the range.

When the external electrode is formed by a coil,
The pitch can be set as desired. Since the pitch of the coil of the external electrode affects the obtained brightness, the pitch of the coil can be appropriately adjusted to achieve a desired brightness distribution in the lamp axis direction. For example, the brightness tends to be relatively large in a region relatively close to the internal electrode, and relatively small in a region relatively far from the internal electrode. To obtain the distribution, the pitch of the coil can be changed according to the distance from the internal electrode. In addition, if necessary, even when it is desired to obtain a predetermined non-uniform brightness distribution in the lamp axis direction, the pitch of the coil of the external electrode can be appropriately changed. Further, as a material for forming the coil of the external electrode, a metal wire is generally used, but if necessary, a conductive material such as a metal, a metal oxide, or a nitride is coated on the outer surface of the light-transmitting airtight container. It may be a film deposited by vacuum deposition, chemical vapor deposition (CVD), or the like. The wire is generally used because a material having a circular cross section is easily available, but a metal wire having an irregular cross section such as a square or a triangle can be used if necessary.

When the external electrode is formed of a mesh structure, a plain weave, a twill weave, or a knitted structure of a metal wire can be used. However, a punched metal plate may be used if necessary. When using a knitted knitted structure, a thicker cylinder is manufactured in advance, a discharge vessel is inserted therein, and then both ends of the knitted knitted structure are pulled to reduce the diameter of the knitted knitted structure. It can be in close contact with the outer peripheral surface of the container.

Further, when the external electrode is formed of a transparent conductive film, an ITO film, a NESA film, or the like can be used.

Further, when the external electrode is made of a metal foil, the metal foil is adhered to one surface of the transparent resin sheet, and the adhesive applied to the other surface of the transparent resin sheet is coated on the outer surface of the transparent airtight container. It can be arranged by adhering to. However, a metal foil can be directly adhered to the outer surface of the discharge vessel. Further, the width of the external electrode may change in the axial direction of the discharge vessel.

<Regarding Phosphor Layer> The phosphor layer is provided on the inner surface side of the translucent airtight container. The “inner side of the translucent airtight container” is defined as a mode in which the phosphor layer is formed directly on the inner surface of the translucent airtight container, and the indirect fluorescent light is applied to the inner surface of the translucent airtight container via a protective film or the like. The meaning includes a mode of forming a body layer.

The phosphor layer is of a light emitting type having three or more wavelengths including at least RGB. Note that "at least RGB
Is a three-wavelength light-emitting phosphor, which means that the three primary colors of light, the red light R, the green light G, and the blue light B, are each efficiently emitted in a relatively narrow wavelength range. Phosphors mainly composed of three kinds that radiate well separately, and phosphors that efficiently emit visible light in a relatively narrow wavelength range in addition to three-wavelength light emitting phosphors, for example, a blue-green region B. G (peak wavelength 500 nm
Around) light emission, deep red region DR (peak wavelength around 660 nm) and green-yellow region GY (peak wavelength 550 n)
m) A phosphor that emits light by emitting one or more phosphors as appropriate and further improving the color rendering properties and the efficiency.

Further, the phosphor layer has a structure in which all the phosphors used are 2.0 ×
It is assumed that the phosphor is configured using a phosphor whose visible light is attenuated within 10 ⁻³ seconds, preferably within 1.5 × 10 ⁻³ seconds, to 1/10 of the normal irradiation. In the present invention, the light output attenuation characteristics of the phosphor are measured by the following method.

1. The fluorescent lamp is turned on at a high frequency under the condition of an ambient temperature of 25 ° C. The lighting frequency is 50 kHz.

2. When the lighting condition of the fluorescent lamp is stable,
The lamp power supply to the fluorescent lamp is instantaneously shut off, and the emission intensity at the peak wavelength of the phosphor layer is measured. The cutoff of the lamp power supply is performed so that the peak value of the lamp current waveform attenuates to 10% or less of the steady-state lighting within 0.1 × 10 ⁻³ seconds from the start of cutoff.

3. The emission intensity at the peak wavelength of the visible light emission of the phosphor is measured by an oscillogram or the like after converting the emission at the peak wavelength extracted by, for example, a spectroscope into an electric signal using a photomultiplier or the like.

4. The time when the lamp power supply is cut off is set as the time when the measurement of the radiation intensity starts, and the time change of the radiation intensity at the peak wavelength of the phosphor is measured. The time during which the radiation intensity attenuates to 10% of the peak value of the radiation intensity during steady lighting is measured, and this value is used as the decay time of the light output of the phosphor.

Further, the phosphor layer emits white light in addition to the above structure. Note that “white” means that the color is located substantially in the center region in the (x, y) chromaticity diagram of the CIE and is in a chromaticity range generally called white. Therefore, for example, a daylight color having a correlated color temperature of 6700K, a daylight color of 5000K, a warm white color of 3500K,
Includes 0K bulb color.

In the present invention, if the phosphor forming the phosphor layer has the above-described structure, the object of the present invention can be achieved by achieving a new and useful action and effect to be described later.
It does not matter essentially whether or not the composition is specific. However, an example of a phosphor that can be actually used is shown in Table 1.

[0034]

Table 1 Phosphor Peak wavelength (nm) Decay time of light output (× 10 ⁻³ sec) Y ₂ O ₂ S: Eu 626 1 YVO ₄ : Eu 620 1 SrA ₂ O ₄ : Eu 492 Less than 0.1 ( Sr, Ca, Ba) ₁₀ (PO ₄ ) ₃ Cl ₂ : less than Eu 453 0.1 BaMgAl ₁₀ O ₁₇ : less than Eu 450 0.1 Next, a phosphor layer is formed on the inner surface side of the translucent airtight container. In this case, a single phosphor layer may be formed by adjusting a coating solution in which a phosphor to be used is mixed, or a plurality of phosphor layers of different phosphors may be formed. Further, the phosphor layer may be formed on the entire peripheral surface of the light emitting region in the longitudinal direction of the light-transmitting airtight container, or a light guide slit in which the phosphor layer is not formed in the tube axis direction to form an aperture structure. You can also.

<Other Configurations> About Translucent Insulating Tube A translucent insulating tube can be provided outside the external electrode to mechanically protect the external electrode and, if necessary, further improve the insulation of the discharge lamp. The translucent insulating tube is preferably transparent. Further, the light-transmitting insulating tube is preferably heat-shrinkable for the workability of installation.

2. About a protective film etc. If necessary, a protective film or an electron emitting material film made of alumina fine particles or the like can be formed on the inner surface of the translucent airtight container. When forming a protective film, a protective film may be formed between the phosphor layer and the inner surface of the translucent airtight container, or a protective film may be formed on the inner surface of the phosphor layer on the discharge space side. Is also good.
Further, an electron emitting material film can be formed, and in this case, it is effective to avoid or reduce the occurrence of darkness characteristics of the fluorescent lamp.

3. Lighting Circuit In the case where the fluorescent lamp has a configuration utilizing arc discharge, a lighting circuit having a configuration in which a low-frequency or high-frequency AC voltage is applied between the counter electrodes via a current-limiting impedance can be used.

On the other hand, when the fluorescent lamp uses a dielectric barrier discharge, the lighting circuit outputs a high-frequency AC voltage having a waveform such as a rectangular wave or a sine wave, or a pulse voltage having a high repetition frequency. It is preferable to use a configuration in which the power is applied directly between the opposing electrodes without using an external current limiting impedance. Note that the pulse voltage can be obtained by half-wave rectification of a high-frequency AC voltage of a rectangular wave or a sine wave. Further, the lighting circuit can be constituted by an inverter.

<Function of the Present Invention> In the present invention, since the light output attenuation characteristic of the phosphor is within 2.0 × 10 ⁻³ seconds and the light output can be changed rapidly, The brightness changes when the lamp blinks rapidly. Then, the appearance of the blinking is remarkably improved. For this reason, for example, when the fluorescent lamp of the present invention is used as a backlight of a liquid crystal display device, the responsiveness of the liquid crystal used is low by blinking the fluorescent lamp in synchronization with each field of the moving image when displaying the moving image. Even
This makes it possible to display a clear moving image. In addition, when the fluorescent lamp of the present invention is used as a light source of a blinking marker light, the appearance of blinking is improved.

The present invention is particularly effective for fluorescent lamps utilizing dielectric barrier discharge. That is,
In the dielectric barrier discharge, since the luminous flux rising characteristic is essentially excellent, the above-mentioned good attenuation characteristic of the light output of the phosphor is synergistically added to the dielectric barrier discharge to show a really good blinking characteristic.

Further, the present invention is suitable as a backlight of a liquid crystal display device or a blinking marker light since the phosphor layer emits white light.

Incidentally, the attenuation characteristic of the optical output is 2.0 × 10
^{If the} time exceeds ^-3 seconds, the above-mentioned effects cannot be obtained, so that it is impossible. On the other hand, if the attenuation characteristic of the optical output is within 1.5 × 10 ⁻³ seconds, a better effect can be obtained. Further, the attenuation characteristic of the optical output is 1.0 × 10 ^−3.
Within seconds, the optimal effect is obtained.

According to a second aspect of the present invention, there is provided a discharge lamp.
In the fluorescent lamp described above, the phosphor layer is Y₂O₂S:
Eu and YVO₄: At least one of Eu and SrA
l ₂O₄: Eu and BaMgAl₁₀O₁₇: Eu and
And (Sr, Ca, Ba)_{1 0}(PO₄)₃Cl₂: Eu
And at least one of the following:
You.

The present invention provides a three-wavelength emission type,
A preferable combination of phosphors whose light output attenuation characteristics fall within a predetermined range is defined. That is, Y ₂ O ₂ S: Eu
And red light emission can be obtained from at least one of YVO ₄ : Eu. From SrAl ₂ O ₄ : Eu,
Green light emission can be obtained. BaMgAl
₁₀ O _{1 7:} Eu and _{(Sr, Ca, Ba) 10} (P
Blue light emission can be obtained from at least one of O ₄ ) ₃ Cl ₂ : Eu.

According to a third aspect of the present invention, there is provided a fluorescent lamp having an elongated and light-transmitting airtight container; a discharge medium sealed in the light-transmitting airtight container to generate ultraviolet rays by discharge; At least one pair of electrodes arranged so as to generate light; emits visible light having a wavelength of 550 nm or more, and emits light at a time of steady irradiation within 2.0 × 10 ⁻³ seconds after blocking ultraviolet irradiation.
A phosphor layer including at least a phosphor whose visible light radiation attenuates to / 10 and disposed on the inner surface side of the translucent airtight container;
It is characterized by having.

According to the present invention, since the light output attenuation characteristic of a phosphor which emits visible light in a wavelength region of 550 nm or more is shortened as described above, this phosphor can be converted into a known blue light-emitting material if necessary. By appropriately combining the phosphor and the green light-emitting phosphor, it is possible to obtain a fluorescent lamp having various emission colors and improved blinking characteristics.

The fourth aspect of the present invention provides a fluorescent lamp according to the third aspect.
In the fluorescent lamp described, the phosphor has a wavelength of 620 nm.
It is characterized by emitting the above visible light.

According to the present invention, since the light output attenuation characteristic of the phosphor which emits visible light in the wavelength region of 620 nm or more is shortened as described above, the phosphor can be attenuated as necessary. By selecting from a group including known blue light emitting phosphors and green light emitting phosphors having excellent characteristics, it is possible to obtain a fluorescent lamp which emits mixed color light and has excellent blinking characteristics.

According to the fifth aspect of the present invention, there is provided a fluorescent lamp according to the third aspect.
Or in the fluorescent lamp according to 4, wherein the phosphor is Y ₂ O
₂ S: Eu and _YVO 4: is characterized in that at least one of Eu.

The present invention defines a configuration that uses a suitable phosphor that can emit red light and has a light output attenuation characteristic falling within a predetermined range. It should be noted that SrAl2O4: Eu is used as a green light-emitting phosphor, and BaMgAl ₁₀ O ₁₇ : Eu and (S
At least one of r, Ca, Ba) ₁₀ (PO ₄ ) ₃ Cl ₂ : Eu can be used in appropriate combination.

The lighting device according to claim 6 includes a lighting device main body;
A fluorescent lamp according to any one of claims 1 to 5, which is provided in a lighting device main body; and a lighting circuit for energizing the fluorescent lamp.

In the present invention, the term “illumination device” is a broad concept including all devices utilizing the light emission of a discharge lamp. For example, a backlight unit, a liquid crystal display device having the same, and a liquid crystal display device are incorporated. Including equipment. Equipment incorporating a liquid crystal display device, for example,
Examples include devices incorporating a liquid crystal display device, such as personal computers, navigation devices, portable information terminals, and liquid crystal television receivers, as well as instrument panel lighting devices for vehicles, such as automobiles, and decorative lighting devices.

The “illumination device main body” refers to the remaining portion of the illumination device excluding the discharge lamp.

[0054]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view and an end view of a cross section showing a first embodiment of a fluorescent lamp according to the present invention.

In the figure, the fluorescent lamp includes a light-transmitting hermetic container 1, an introduction line 2, a phosphor layer 3, a discharge medium, an internal electrode 4, and an external electrode 5.

The translucent airtight container 1 has an elongated glass bulb 1a and an end portion 1b sealing the open end of the glass bulb 1a. The end portion 1b of the translucent airtight container 1 is mainly composed of a glass bead stem.

The introduction line 2 penetrates the end portion 1b of the translucent airtight container 1 in an airtight manner, and the airtight penetrating portion is made of at least a sealing metal Kovar. Although not shown, a nickel wire is welded to the outer end of Kovar to facilitate connection of the lighting circuit.

The phosphor layer 3 is made of a phosphor of the following three wavelength emission type, and is formed on the inner surface of the translucent airtight container 1. That is, the phosphor of the three-wavelength emission type is Y ₂ O ₂ S:
Eu, SrAl ₂ O ₄ : Eu and BaMgAl ₁₀ O
₁₇ : A single phosphor layer is formed by blending Eu.

A discharge medium is sealed inside the translucent airtight container 1, and the discharge medium is composed of a rare gas mainly composed of xenon.

The internal electrode 4 is formed of a cold cathode,
And is sealed in one end of the translucent airtight container 1. The external electrode 5 is made of metal foil, and is adhered to the outer surface of the translucent airtight container 1 in an arc shape. The metal foil is, for example, an aluminum foil, and a material adhered to a transparent resin thin plate substrate can be used.

When a high-frequency voltage is applied by connecting a lighting circuit (not shown) between the internal electrode 4 and the external electrode 5 of the fluorescent lamp without using an external current-limiting impedance, both electrodes are connected. A dielectric barrier discharge occurs between 4 and 5, and the xenon of the discharge medium sealed in the translucent airtight container 1 emits ultraviolet rays. Ultraviolet light is applied to the phosphor layer 3
, The phosphor is excited to emit visible light. The emitted visible light is white. Since the light is led out from the portion where the external electrode 5 is not provided, visible light can be used as a lighting device.

Each of the phosphors constituting the phosphor layer 3 has a light output attenuation characteristic of 1 × 10 ⁻³ seconds or less, so that the flickering characteristics of the fluorescent lamp are extremely excellent.

FIG. 2 is a graph showing a change in light output after the lamp power is cut off in the first embodiment of the fluorescent lamp of the present invention, together with that of the comparative example.

In the figure, the horizontal axis shows the elapsed time (seconds) after the lamp power is cut off, and the vertical axis shows the light quantity (%). In the figure, a curve A indicates the present embodiment, and a curve B indicates a comparative example. In the comparative example, the phosphor layer 3 is Y
₂ O ₃ : Eu, LaPO ₄ : Ce, Tb and BaMg
The specifications are the same as those of the present embodiment except that it is made of Al ₁₀ O ₁₇ : Eu.

As can be understood from FIG.
Then, the attenuation characteristic of the optical output is 1 × 10 ^-3Less than a second
However, the comparative example is 5 × 10^-3It turns out that it takes seconds.

Hereinafter, another embodiment of the present invention will be described with reference to FIGS. In each figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 3 is a partially cutaway front view showing a second embodiment of the discharge lamp of the present invention.

In the present embodiment, the external electrode 5 is formed by winding a metal wire in a coil shape, and the inner surface thereof is
Is in contact with the outer circumferential surface of the
1 and that the lighting circuit 12 is configured to light the lighting circuit.

The lighting circuit 12 is connected between the internal electrode 4 and the external electrode 5 via the lead-in line 2, and lights the fluorescent lamp by applying a high-frequency pulse voltage to the fluorescent lamp.

FIG. 4 is a front view of a partially cutaway longitudinal section and a cross-sectional end view showing a third embodiment of the discharge lamp of the present invention.

This embodiment is different in that a pair of external electrodes 5A and 5B are provided on the outer surface of the translucent airtight container 1 so as to be spaced apart from each other.

FIG. 5 is a partially cutaway longitudinal section showing a fourth embodiment of the discharge lamp of the present invention.

This embodiment is different from the first embodiment in that a pair of internal electrodes 4A and 4B are provided inside both ends of the translucent airtight container 1.

FIG. 6 is a cross-sectional view of a principal part showing a backlight device for a liquid crystal as one embodiment of the illumination device of the present invention.

In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals. Reference numeral 6 denotes a backlight device main body, 7 denotes a fluorescent lamp, and 8 denotes a liquid crystal display.

<Regarding Backlight Device Main Body 6> The backlight device main body 6 includes a light guide 6a, a gutter-shaped reflecting plate 6b,
It includes a rear reflector 6c, a diffuser 6d1, and a light collector 6d2, and is housed in a case (not shown).

The light guide 6a is made of a transparent material having a high refractive index, such as a transparent acrylic resin. The gutter-shaped reflecting plate 6b reflects light emitted from the fluorescent lamp 7 in a direction not directly incident on the light guide 6a and causes the light to enter the light guide 6a, and emits light from the fluorescent lamp 7 other than the light guide 6a. Shield so that light does not leak to the location. The back reflector 6c reflects light emitted from the back of the light guide 6a and emits the light from the front of the light guide 6a. In this case, the reflectance of the back reflector 6c can be partially controlled so that light is emitted from the entire surface as uniformly as possible. The diffusion plate 6d1 is a light guide 6
The light emitted from the light guide 6a to the front is diffused to make the luminance distribution as uniform as possible. Light collector 6
d2 condenses the light emitted from the diffusion plate 6d1 and increases the incidence efficiency with respect to the liquid crystal display unit 8.

<About the Fluorescent Lamp 7> The fluorescent lamp 7 and a lighting circuit (not shown) have the structure shown in FIG.

<Regarding the Liquid Crystal Display 8> The liquid crystal display 8
Is disposed so as to overlap the front surface of the backlight device main body 6,
It is illuminated from the back by the backlight body 6, and a transmissive liquid crystal display is performed.

[0081]

According to the first to sixth aspects of the present invention, an elongated light-transmitting airtight container, a discharge medium sealed in the light-transmitting airtight container, and at least one pair of discharge media arranged to generate a discharge are provided. 2.0 × 10 after blocking the electrode and UV irradiation
A phosphor layer disposed on the inner surface side of a light-transmitting hermetic container using a phosphor whose visible light attenuates to 1/10 of that during steady irradiation within ^-3 seconds; Can provide a fluorescent lamp having excellent attenuation characteristics.

According to the first aspect of the present invention, in addition, the phosphor layer emits white light using a phosphor of at least three wavelengths including RGB, thereby emitting white light, which is suitable as a backlight of a liquid crystal display device. It is possible to provide a simple fluorescent lamp.

According to the second aspect of the present invention, red light emission is additionally provided.
Is Y₂O₂S: Eu and YVO ₄: At least Eu
Kind of green light emission is SrAl₂O₄: Eu, blue emission B
aMgAl₁₀O₁₇: Eu and (Sr, Ca, B
a)₁₀(PO₄)₃Cl₂: At least one of Eu
To provide a fluorescent lamp that obtains white light using a phosphor
Can be. According to the third aspect of the present invention, in addition, the phosphor layer
Emit visible light of wavelength 550nm or more and irradiate with ultraviolet light
2.0 × 10^-31/1 of normal irradiation within seconds
Including at least a phosphor whose visible light emission attenuates to zero
To obtain a variety of emission colors
Offers a fluorescent lamp that is capable of flashing and has improved flashing characteristics
can do.

According to the fourth aspect of the present invention, the phosphor emits visible light having a wavelength of 620 nm or more, so that the phosphor emits a known green and blue light having excellent light output attenuation characteristics. It is possible to emit a mixed color light by selecting from the group including the fluorescent substance, and to provide a fluorescent lamp excellent in blinking performance.

According to the fifth aspect of the present invention, in addition, since the phosphor is at least one of Y ₂ O ₂ S: Eu and YVO ₄ : Eu, red emission can be obtained from the phosphor. In addition, it is possible to provide a suitable fluorescent lamp whose light output attenuation characteristic falls within a predetermined range.

According to the invention of claim 6, it is possible to provide a lighting device having the effects of claims 1 to 5.

[Brief description of the drawings]

FIG. 1 is a front view of a partially cutaway longitudinal section and an end view of a transverse section showing a first embodiment of a fluorescent lamp of the present invention.

FIG. 2 is a graph showing a change in light output after lamp power is cut off in the first embodiment of the fluorescent lamp of the present invention, together with that of a comparative example.

FIG. 3 is a partially cutaway front view showing a second embodiment of the fluorescent lamp of the present invention.

FIG. 4 is a front view of a partially cutaway longitudinal section and an end view of a transverse section showing a third embodiment of the fluorescent lamp of the present invention.

FIG. 5 is a longitudinal sectional view showing a fourth embodiment of the fluorescent lamp of the present invention.

FIG. 6 is an essential part cross-sectional view showing a liquid crystal backlight device as one embodiment of the illumination device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Translucent airtight container 1a ... Glass bulb 1b ... End part 2 ... Introductory line 3 ... Phosphor layer 4 ... Internal electrode 5 ... External electrode

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C09K 11/84 CPD C09K 11/84 CPD F term (Reference) 4H001 CA07 XA08 XA12 XA13 XA15 XA16 XA17 XA20 XA23 XA38 XA39 XA56 YA63 5C043 AA20 BB04 CC09 CD01 DD28 EB04

Claims (6)

[Claims] 1. An elongated light-transmitting airtight container; a discharge medium sealed in the light-transmitting airtight container to generate ultraviolet rays by discharge; and a discharge medium disposed in the light-transmitting airtight container. , At least a pair of electrodes; a light emitting type of at least three wavelengths including RGB, and 2.0 ×
A phosphor layer that emits white light and is disposed on the inner surface side of the translucent airtight container using a phosphor whose visible light emission attenuates to 1/10 of the normal irradiation within 10 ⁻³ seconds; A fluorescent lamp comprising: 2. A phosphor layer comprising Y ₂ O ₂ S: Eu and YV
At least one of O ₄ : Eu and SrAl ₂ O ₄ : Eu
And BaMgAl ₁₀ O ₁₇ : Eu and (Sr, C
_2. The fluorescent lamp according to claim 1, comprising: a, Ba) ₁₀ (PO ₄ ) ₃ Cl ₂ : Eu. 3. An elongated translucent airtight container; and a translucent airtight container.
At least one pair arranged to generate a discharge in the
An electrode; emits visible light having a wavelength of 550 nm or more, and is purple
2.0 × 10 after blocking external radiation ^-3At regular irradiation within seconds
Less phosphors whose visible light emission attenuates to 1/10 of
Phosphor layer disposed on the inner surface side of the translucent airtight container
And a fluorescent lamp comprising: 4. The fluorescent lamp according to claim 3, wherein the phosphor emits visible light having a wavelength of 620 nm or more. 5. The phosphor is composed of Y ₂ O ₂ S: Eu and YVO.
_4. The fluorescent lamp according to claim 3, wherein the fluorescent lamp is at least one of Eu. 6. A lighting device main body; and the fluorescent lamp according to claim 1 disposed on the lighting device main body;
A lighting circuit for energizing a fluorescent lamp;