JP3922072B2 - Fluorescent lamp and lighting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluorescent lamp and a lighting fixture.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a multi-lamp lighting apparatus including a plurality of fluorescent lamps and a plurality of ballasts that respectively light the plurality of fluorescent lamps has been provided.
[0003]
[Problems to be solved by the invention]
In a multi-lamp lighting fixture, when any one of a plurality of fluorescent lamps is lit, the light of the fluorescent lamp that is initially lit is applied to the fluorescent lamp that is not yet lit, and the fluorescent lamp There was a problem that the starting voltage of the engine increased, making it difficult to start.
[0004]
In order to prevent the startability of the fluorescent lamp from deteriorating due to the above phenomenon, each ballast can be designed in consideration of the increase in the start voltage so that a higher start voltage can be generated. However, when such a design is performed, there is a problem that the manufacturing cost of the ballast increases because a starting voltage higher than the originally required starting voltage is generated.
[0005]
In addition, the starting order of the plurality of fluorescent lamps is determined in advance, and only the fluorescent lamps in the order in which light brighter than the predetermined illuminance is incident at the time of starting (for example, only the fluorescent lamp that is lit last) are increased. It is also conceivable to use a ballast that can generate a high starting voltage in consideration. With this method, it is not necessary to use high-cost ones for all ballasts, and only a part of the ballasts need to be high-cost. It is difficult to design a ballast because it is necessary to predict how much the starting voltage will increase at the time of designing, and the increase in starting voltage varies greatly depending on the usage environment.
[0006]
The present invention has been made in view of the above problems, and its purpose is to increase the starting voltage by the light from the previously lit fluorescent lamp when lighting multiple fluorescent lamps, An object of the present invention is to provide a fluorescent lamp and a luminaire that are prevented from becoming difficult to start.
[0007]
[Means for Solving the Problems]
As described above, when a non-lighted fluorescent lamp is irradiated with light from the outside, the starting voltage of the lamp increases and it becomes difficult to start. The cause of this phenomenon is specified. Therefore, the present inventors conducted an experiment in which a fluorescent lamp is irradiated with light from a spectral lamp or light from a tungsten halogen lamp to measure a change in starting voltage. In addition, in the experiment using the spectrum lamp, the experiment was performed for the case where the entire fluorescent lamp was irradiated with light (overall radiation) and the case where a part of the fluorescent lamp was irradiated with light (local radiation). In addition, in the experiment with a tungsten halogen lamp, both the total radiation and the local radiation were experimented. In the local radiation, the experiment using the full spectrum and the experiment using the partial spectrum performed by cutting out light of a specific wavelength were performed.
[0008]
The fluorescent lamp to be measured was a straight tube type with a rated power of 20 W and a distance between electrodes of 50 cm, and a phosphor not coated. FIG. 4 is a schematic view of the experimental apparatus, and the fluorescent lamp 1 is irradiated with light from a test light source (not shown) directly or through the slit 20. A direct current power source E is connected between the electrodes 3a and 3b of the fluorescent lamp 1 via a current limiting resistor R. The output voltage of the direct current power source E is gradually increased, and the fluorescent lamp 1 starts discharging. The change in the starting voltage was observed by measuring the output voltage of the DC power supply E (this output voltage is called the discharge start voltage).
[0009]
First, as a result of experiments using mercury, argon, helium, krypton, hydrogen, and iodine spectrum lamps as light sources for testing, the magnitude of the rise range is large regardless of the light emitted from any spectrum lamp. Although there was an increase in the discharge starting voltage was observed. Further, when the light irradiation area of the light source is limited to a square area having a side of 30 mm by the slit 20, and the change in the discharge start voltage is measured by shifting the irradiation position, the distance from the anode electrode 3a is within a range up to about 10 cm. It was found that only when the light was irradiated, the rise of the discharge start voltage was observed, and the rise width became maximum at a position several cm from the anode electrode 3a.
[0010]
Next, the following three experiments were performed using a tungsten halogen lamp (type: JC25V150W) having a rated voltage of 24V and a power consumption of 150W as a test light source. In the whole radiation experiment, the tungsten halogen lamp was placed 50 cm ahead of the fluorescent lamp 1, and the light of the tungsten halogen lamp was changed while the light of the tungsten halogen lamp was irradiated on the whole of the fluorescent lamp 1. went. As a result, with the radiant flux corresponding to the illuminance of 1 to 2 (lx), an increase in the discharge start voltage begins to be observed, and thereafter, the light output of the tungsten halogen lamp increases and the discharge start voltage increases uniformly. It has been found that above the radiant flux corresponding to 300 to 400 (lx), the increase in the discharge start voltage becomes a substantially constant value (about 200 V).
[0011]
Further, in the local radiation experiment using the full spectrum, the tungsten halogen lamp light is changed by 2V from 0V to 24V, and the power of the tungsten halogen lamp is changed by 2mm and 5mm by the lens. A change in the discharge start voltage was observed by changing the irradiation area at regular intervals along the axial direction of the fluorescent lamp 1 (2 cm intervals on the anode side and 4 cm intervals on the cathode side). FIG. 5 shows the measurement results of the discharge start voltage when the distance from the anode electrode 3a to the irradiation position is changed, and a, b, c, d, e, f, g, h, i, j, k, l and m are the measurement results when the power supply voltage of the tungsten halogen lamp is 0V, 2V, 4V, 6V, 8V, 10V, 12V, 14V, 16V, 18V, 20V, 22V and 24V, respectively. Show. From this measurement result, when light is irradiated in the range of 4 to 6 cm from the anode electrode 3a, the increase width of the discharge start voltage becomes the largest, and the discharge start voltage is higher than the radiant flux corresponding to illuminance of 20,000 lx. It has been found that the increase width of is substantially constant (about 200 V). Basically, the discharge start voltage rises only when the distance from the anode electrode 3a to the light irradiation position is in the range of 0 to 10 cm, but when the irradiation light becomes brighter than the radiant flux corresponding to the illuminance of 1000 lx. An increase in the discharge starting voltage, which seems to be due to scattered light, was observed.
[0012]
Furthermore, in a local radiation experiment using a partial spectrum, monochromatic light having a wavelength width of 6.4 nm is cut out from the light of a tungsten halogen lamp using a monochromator (model number G-250 manufactured by Nikon Corporation), and a range of 300 to 800 nm. Then, the fluorescent lamp was irradiated with light whose wavelength was changed every 5 nm, and the change in the discharge start voltage was measured. Note that the light irradiation range is a square area of 2 mm in length and 2 mm in width, or a circular area of 1.5 mm in diameter, and the distance from the anode electrode 3a to the light irradiation position is changed by 2 cm from 0 cm to 10 cm. went. FIG. 6 shows the measurement results when the distance from the anode electrode 3a to the light irradiation position is 6 cm. When light having a wavelength of 500 nm to 800 nm was irradiated, no increase in the discharge start voltage was observed. . In addition, when light having a wavelength of 300 nm to 500 nm is irradiated, wavelength dependency is confirmed such that the discharge start voltage has a maximum value (the increase width is about 100 V) in the wavelength range of 370 nm to 380 nm. The wavelength dependency of such a discharge start voltage hardly changed even when the irradiation position was changed.
[0013]
In this way, the discharge start voltage required for direct current lighting is measured in a state where light of various spectra is irradiated onto a straight tube fluorescent lamp having an electrode interval of 50 cm without applying a phosphor, and the fluorescent lamp 1 As a result of experimentally examining the influence of the irradiated light on the starting characteristics, it was found that the distance from the anode electrode was in the range of 0 to 15 cm (the influence was large). No Causes a rise in the discharge start voltage only when light is irradiated to a range of 0 to 10 cm, and the maximum rise of the discharge start voltage is about 220 V at a position several cm from the anode electrode, and more than 300 nm. Further, it was found that only when light having a wavelength component of 500 nm or less was irradiated, the discharge start voltage was increased, and the discharge start voltage was maximized when the wavelength was around 370 to 380 nm.
[0014]
By the way, in order to start the fluorescent lamp, it is necessary that one (or several) electrons are accelerated by the electric field, collide with the discharge gas enclosed in the arc tube, and cause ionization. Then, the electrons generated by ionization further cause ionization, and the density of pairs of electrons and ions becomes very high. The ions reach the cathode, and one or more electrons are emitted from the cathode. This ionization phenomenon continues. The condition for satisfying this situation is the starting condition.
[0015]
In general, a fluorescent lamp contains a discharge gas composed of a mixed gas of argon and mercury, and the ionization voltage of mercury is lower than that of argon, but the density of mercury is two or more orders of magnitude lower than that of argon. The probability of collision with argon is higher than the probability of collision with mercury, and argon has a great influence on the starting characteristics of the fluorescent lamp. The outline of the mechanism when the fluorescent lamp is started will be described below.
[0016]
When electrons accelerated by the electric field collide with argon, the argon is excited by the kinetic energy of the electrons, and the excited argon immediately emits light and returns to the ground state. At this time, argon stays at the excitation level for several nanoseconds to several tens of nanoseconds.
[0017]
On the other hand, when argon is excited to a level called a metastable state, the life of the excited level becomes long because this level is a region where light cannot be emitted. When argon excited to a metastable state collides with mercury, the excitation energy is given to mercury. The excited level energy of argon excited to a metastable state is slightly larger than the ionization energy of mercury, so mercury is ionized (this phenomenon is known as the Penning effect). Also, the argon metastable atoms themselves may cause cumulative ionization, and the presence of argon atoms excited to the metastable state is essential for starting a fluorescent lamp.
[0018]
Since the presence of argon atoms excited in such a metastable state is indispensable for starting a fluorescent lamp, the cause of an increase in the starting voltage of a fluorescent lamp when light from another fluorescent lamp is irradiated is The present inventors considered that the density of argon atoms excited to a metastable state is to be reduced by light irradiation. Hereinafter, the reason why it becomes difficult to start the fluorescent lamp when the fluorescent lamp is irradiated will be described with reference to FIG. When light strikes an atom in the metastable state (state C in the figure), the light is absorbed and transitions to a higher excited state (state A in the figure). This state has a short lifetime as described above, and immediately emits light to change to another state (state B in the figure), and further emits light from this state B to cause a ground state (state D in the figure). ). Actually, there are things that return from the metastable state C to the ground state D via states other than the states A and B, but basically they can be understood with the same idea. Of course, there are those that transition from the metastable state to another state and then return to the metastable state, but the number is very small. Here, in order to generate excitation due to light absorption, light having a spectrum corresponding to the transition width (for example, the energy difference between the state A and the metastable state C) needs to be incident. In addition, the wavelength was found to be 300 nm or more and 500 nm or less.
[0019]
Further, it has been found from the above experimental results that the light irradiation position affects the starting voltage, and the reason will be described below. In the case of a fluorescent lamp, the electrodes are sufficiently heated before starting to emit thermal electrons, and the electrons emitted from the cathode are accelerated by a starting voltage (electric field) applied between the electrodes to obtain energy. As described above, argon is sealed inside the fluorescent lamp, and the electrons move toward the anode while repeatedly acquiring energy from the electric field and losing energy due to collision with argon atoms. Therefore, a considerable distance is required to obtain energy for the electrons to excite argon to the metastable state, and a predetermined energy is reached only after reaching a location near the anode. In the above experimental results, the energy can be acquired only after reaching a range within about 15 cm from the anode, and it is presumed that the metastable atoms of argon are finally generated at that location. Here, when light enters a region where metastable atoms exist (that is, a region within a distance of about 15 cm from the anode), argon metastable atoms generated by collision with electrons enter the region. After the light is absorbed and transitions to a higher excited state, it is extinguished by emitting light and returning to the ground state. Therefore, when this region is irradiated with light, the discharge start voltage rises. On the other hand, even if light is irradiated to other regions, there is no change in the discharge start voltage because there is no argon metastable atom in that place. Note that the location where argon metastable atoms are generated depends on the length of the fluorescent lamp, the discharge gas sealing pressure, and the voltage applied at start-up. Each instrument needs to be evaluated.
[0020]
As described above, the present inventors have found that the reason why the starting voltage rises by irradiating light to an unlit fluorescent lamp from the outside is the metastable state of argon, which plays an important role when starting the lamp. If we think that atoms are to be extinguished by external light irradiation and prevent the argon metastable atoms from being lost by external light irradiation, the starting voltage can be prevented from rising. The present invention was carried out by paying attention to the wavelength of light that may cause the metastable atoms of argon to disappear and the place where the metastable atoms exist.
[0021]
That is, in order to achieve the above-mentioned invention, in the invention of claim 1, a fluorescent tube is formed on the inner surface and a discharge tube containing at least argon inside is enclosed, and provided at both ends of the discharge tube. With electrodes, wavelength 3 00nm or more, and 5 Less than 00nm All of While preventing light from entering the arc tube from the outside All light with a wavelength less than 300 nm and all with a wavelength greater than 500 nm The light-emitting tube is provided with a light-shielding means for transmitting the light.
[0022]
According to a second aspect of the present invention, in the first aspect of the present invention, the light shielding means comprises a light shielding film formed on the surface of the arc tube.
[0023]
According to a third aspect of the present invention, in the second aspect of the present invention, the light-shielding film is formed at least on the surface of the arc tube at a location near the electrode that causes an increase in starting voltage due to the incidence of light. .
[0024]
In the invention of claim 4, a fluorescent lamp having a phosphor film formed on the inner surface and enclosing therein a discharge medium containing at least argon, and a plurality of fluorescent lamps each having electrodes provided at both ends of the arc tube, The fixture body to which multiple fluorescent lamps are attached, and the wavelength of light emitted from each fluorescent lamp to other fluorescent lamps 3 00nm or more, and 5 Less than 00nm All of While shielding light All light with a wavelength less than 300 nm and all with a wavelength greater than 500 nm The instrument main body is provided with a light shielding means for transmitting the light.
[0025]
In the invention of claim 5, in the invention of claim 4, the light shielding means has a wavelength. 3 00nm or more, and 5 Less than 00nm All of It has light shielding properties against light All light with a wavelength less than 300 nm and all with a wavelength greater than 500 nm It is characterized by comprising a light shielding member disposed between adjacent fluorescent lamps.
[0026]
In the invention of claim 6, in the invention of claim 5, the light shielding member is disposed on the surface of the arc tube so as to shield at least a portion in the vicinity of the electrode that causes an increase in starting voltage due to incidence of light. It is characterized by.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
An embodiment of a fluorescent lamp according to the present invention will be described with reference to FIGS. A fluorescent lamp 1 shown in FIG. 1A is a straight tube lamp having an electrode interval of, for example, about 50 cm, a fluorescent tube 2 having a phosphor film formed on the inner surface and a discharge medium containing argon inside, and Electrodes 3 a and 3 b provided at both ends of the arc tube 2 are provided, and light shielding films 4 as light shielding means are respectively applied to the surfaces of both ends of the arc tube 2.
[0028]
The light-shielding film 4 is made of a dielectric multilayer film having a light-shielding property with respect to light having a wavelength of 300 nm or more and about 500 nm or less, and is transmissive with respect to light of other wavelengths. It is formed along the path from the electrodes 3a, 3b to a distance of about 15 cm. In the present embodiment, a dielectric multilayer film is used as the light shielding film 4. However, it is only necessary to be able to shield external light having a wavelength of 300 nm or more and about 500 nm or less, and the most desirable is that the wavelength is 300 nm or more. It is a semi-transmissive film in which light of 500 nm or less does not enter from the outside but transmits from the inside to the outside.
[0029]
When the fluorescent lamp 1 is started, argon metastable atoms are generated in the arc tube 2 near the electrodes 3a and 3b by collision with electrons, and there are metastable atoms. Is irradiated with light having a wavelength of 300 nm or more and about 500 nm or less, the atoms in the metastable state of argon disappear and the starting voltage rises. However, in this embodiment, light is incident on the surface of the arc tube 2. As a result, the light shielding film 4 is applied to a portion in the vicinity of the electrodes 3a and 3b that causes an increase in the starting voltage, that is, a distance of about 15 cm from the electrodes 3a and 3b. Therefore, the light-shielding film 4 can prevent light having a wavelength of 300 nm or more and about 500 nm or less from entering the arc tube 2, preventing the disappearance of argon metastable atoms due to the incidence of light, An increase in the starting voltage can be prevented, and the fluorescent lamp 1 can be easily started.
[0030]
Here, from the above experimental results, it has been found that in a straight tube lamp with an electrode interval of 50 mm, argon metastable electrons exist within a distance of about 15 cm from the electrodes 3a and 3b. Therefore, in this embodiment, the light-shielding film 4 is formed to a distance of about 15 cm from the electrodes 3a and 3b, but the region where argon metastable atoms are present differs depending on the type of the fluorescent lamp 1 and the starting voltage. In some cases, it is necessary to apply the light-shielding film 4 also to the central portion in the longitudinal direction of the arc tube 2, and the part where the light-shielding film 4 is applied may be set as appropriate.
[0031]
In the embodiment shown in FIG. 1 (a), the straight tube fluorescent lamp 1 has been described as an example. However, the fluorescent lamp 1 is not intended to be limited to a straight tube type. For example, FIG. 1 (b) As shown in FIG. 1, an FPL-type compact fluorescent lamp 1 ′ having a U-shaped arc tube 2 ′ provided with electrodes 3a and 3b at both ends, and one end as shown in FIG. An FDL type having two U-shaped arc tubes 2 ′ provided with electrodes 3a and 3b, respectively, and connecting the other ends of the arc tubes 2 ′ and 2 ′ to each other to form one discharge path. In the compact fluorescent lamp 1 ″, the light-shielding film 4 may be formed in the vicinity of the electrodes 3a and 3b that cause the starting voltage to increase due to the incidence of light on the surface of the arc tube 2 ′. It is possible to prevent the starting voltage from rising due to the irradiation of light from the outside.
[0032]
(Embodiment 2)
Embodiment of the lighting fixture which concerns on this invention is described based on FIG.2 and FIG.3. A lighting fixture 10 shown in FIG. 2A includes three straight tube fluorescent lamps 1, a lighting device (not shown) for lighting the three fluorescent lamps 1, respectively, and the fluorescent lamp 1 and the lighting device. And an instrument body 11 to be attached. As shown in FIG. 2 (b), the instrument main body 11 is formed in a box shape with an open bottom surface, and the interior thereof is partitioned into three storage chambers by a light shielding plate 12 as a light shielding member. The lamp 1 is accommodated.
[0033]
Each light-shielding plate 12 is formed in a long and thin plate shape with a light-transmitting material, and its surface has a light-shielding property for light having a wavelength of 300 nm or more and about 500 nm or less, and for light of other wavelengths. A dielectric multilayer film having transparency is formed and disposed between adjacent fluorescent lamps 1. Here, when the fluorescent lamp 1 is started, argon metastable atoms are generated inside the arc tube 2 near the electrodes 3a and 3b due to collision with electrons, and the metastable atoms are generated. When light having a wavelength of 300 nm or more and about 500 nm or less is irradiated to an existing site, the metastable atoms of argon disappear and the starting voltage rises. In this embodiment, however, between adjacent fluorescent lamps 1 Since the light-shielding plate 12 is disposed in the light-shielding plate 12, the light emitted from the fluorescent lamp 1 that is initially turned on by the light-shielding plate 12 is shielded from entering the other fluorescent lamps 1 with a wavelength of 300 nm or more and about 500 nm or less. It is possible to prevent the metastable atoms of argon from disappearing due to the incidence of light, to prevent an increase in starting voltage, and to easily start a fluorescent lamp.
[0034]
In the present embodiment, a dielectric multilayer film having a light shielding property with respect to light having a wavelength of 300 nm or more and about 500 nm or less is formed on the surface of the light shielding plate 12. The light-shielding means may be composed of a device that can control the light transmittance (for example, a combination of deflection plates or a liquid crystal) so that the light transmittance is small and the transmittance is large after lighting.
[0035]
Further, the light shielding plate 12 is disposed from one end side to the other end side in the longitudinal direction of the arc tube 2 and shields substantially the entire arc tube 2. You may arrange | position so that only the site | part (for example, the range from the electrode about 15 cm) near an electrode which raises a starting voltage may be shielded.
[0036]
In the embodiment shown in FIG. 2, the multi-lighting lighting fixture 10 using the straight tube type fluorescent lamp 1 has been described as an example. However, the lighting fixture is a type using the straight tube type fluorescent lamp 1. For example, as shown in FIGS. 3 (a) and 3 (b), a hemispherical instrument body 13 having an open bottom surface and two FDL-type compact forms attached to the interior of the instrument body 13 are not intended. In a luminaire 10 including a fluorescent lamp 1 ″ and a lighting device (not shown) for lighting the fluorescent lamp 1 ″, light from one fluorescent lamp 1 has a wavelength of about 300 nm or more and about 500 nm or less. May be provided with a light shielding member 14 for preventing the other fluorescent lamp 1 from being irradiated. The light shielding member 14 is formed in a cylindrical shape with a material having translucency, and the surface thereof has a light shielding property with respect to light having a wavelength of 300 nm or more and about 500 nm or less, and is transparent to light with other wavelengths. A dielectric multilayer film having optical properties is formed. The light shielding member 14 is disposed so as to surround one of the fluorescent lamps 1 ″, and shields a portion near the electrode on the surface of the arc tube 2 ′. It is possible to block light having a wavelength of 300 nm or more and about 500 nm or less that is irradiated from the fluorescent lamp 1 that is initially turned on, from entering other fluorescent lamps 1. It is possible to prevent extinction, to prevent an increase in starting voltage, and to easily start a fluorescent lamp.
[0037]
In the embodiment shown in FIGS. 3A and 3B, a dielectric multilayer film having a light shielding property with respect to light having a wavelength of 300 nm or more and about 500 nm or less is formed on the surface of the light shielding member 14, for example. The light-shielding means is a light-transmitting device that can control the light transmittance so that the light transmittance is small before the fluorescent lamp 1 is started and the light transmittance is large after lighting (for example, a combination of deflection plates or liquid crystal). It may be configured.
[0038]
【The invention's effect】
As described above, the invention of claim 1 includes a luminous tube in which a phosphor film is formed on the inner surface and a discharge medium containing at least argon is enclosed therein, and electrodes provided on both ends of the luminous tube, wavelength 3 00nm or more, and 5 Less than 00nm All of While preventing light from entering the arc tube from the outside All light with a wavelength less than 300 nm and all with a wavelength greater than 500 nm The light-emitting means has a light-shielding means that transmits light of 3 00nm or more, and 5 When light of 00 nm or less is incident, the metastable atoms of argon generated inside the arc tube due to collision with electrons disappear and the starting voltage of the fluorescent lamp rises. Since it is prevented from entering the inside of the arc tube, it is possible to prevent the metastable atoms of argon from disappearing and to prevent the starting voltage of the fluorescent lamp from increasing. Therefore, when a plurality of fluorescent lamps are lit, there is an effect that it is possible to prevent the light from the previously lit fluorescent lamp from entering and becoming difficult to light.
[0039]
According to a second aspect of the present invention, in the first aspect of the present invention, the light shielding means comprises a light shielding film formed on the surface of the arc tube, and has the same effect as the first aspect of the invention.
[0040]
The invention of claim 3 is characterized in that, in the invention of claim 2, the light-shielding film is formed at least on the surface of the arc tube at a portion in the vicinity of the electrode that causes an increase in starting voltage by the incidence of light, Since atoms in the metastable state of argon exist in the vicinity of the electrode, by forming a light-shielding film in the vicinity of the electrode that causes an increase in starting voltage due to the incidence of light, by the incidence of light from the outside, This has the effect of preventing the metastable atoms of argon from disappearing and preventing the starting voltage of the fluorescent lamp from increasing.
[0041]
The invention of claim 4 is a fluorescent lamp having a fluorescent film formed on the inner surface and a discharge tube containing a discharge medium containing at least argon inside, and a plurality of fluorescent lamps each having electrodes provided at both ends of the discharge tube, The fixture body to which multiple fluorescent lamps are attached, and the wavelength of light emitted from each fluorescent lamp to other fluorescent lamps 3 00nm or more, and 5 Less than 00nm All of While shielding light All light with a wavelength less than 300 nm and all with a wavelength greater than 500 nm The instrument body is provided with a light-blocking means that allows light to pass through. 3 00nm or more, and 5 When light of 00 nm or less enters, the metastable atoms of argon generated inside the arc tube due to collision with electrons disappear and the starting voltage of the fluorescent lamp rises. Prevents other fluorescent lamps from being irradiated with light of the above wavelength, which prevents the disappearance of argon metastable atoms due to light irradiation and increases the starting voltage of the fluorescent lamp. There is an effect that can be prevented. Therefore, when lighting a plurality of fluorescent lamps, it is possible to realize a lighting fixture that prevents light from the previously lit fluorescent lamp from entering and preventing an unlit fluorescent lamp from becoming difficult to light.
[0042]
According to a fifth aspect of the invention, in the invention of the fourth aspect, the light shielding means has a wavelength. 3 00nm or more, and 5 Less than 00nm All of It has light shielding properties against light All light with a wavelength less than 300 nm and all with a wavelength greater than 500 nm The light-transmitting material is a light-shielding member disposed between adjacent fluorescent lamps, and has the same effects as the invention of claim 4.
[0043]
According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the light shielding member is disposed on the surface of the arc tube so as to shield at least a portion in the vicinity of the electrode that causes an increase in starting voltage due to incidence of light. Since the atoms in the metastable state of argon are present in the vicinity of the electrode, light from the outside can be obtained by shielding the portion in the vicinity of the electrode that causes an increase in starting voltage by the incidence of light with a light shielding member. Is effective in preventing the metastable atoms of argon from disappearing and preventing the starting voltage of the fluorescent lamp from increasing.
[Brief description of the drawings]
1A to 1C are external perspective views of a fluorescent lamp according to Embodiment 1. FIG.
FIGS. 2A and 2B show a lighting apparatus according to a second embodiment, wherein FIG. 2A is a view seen from below, and FIG. 2B is an external perspective view of the apparatus main body.
FIGS. 3A and 3B show another lighting apparatus according to the embodiment, in which FIG. 3A is a view seen from the lower side, and FIG.
FIG. 4 is a schematic configuration diagram of a measuring apparatus that measures a discharge start voltage of a fluorescent lamp.
FIG. 5 is a diagram showing a measurement result of a local radiation experiment of the entire spectrum, and showing a change in discharge start voltage with respect to a distance from an anode electrode to an irradiation position.
FIG. 6 is a diagram showing a measurement result of a partial spectrum local radiation experiment and showing a change in a discharge start voltage with respect to a wavelength of irradiation light.
FIG. 7 is an energy band diagram for explaining a phenomenon in which atoms in a metastable state of argon disappear.
[Explanation of symbols]
1,1 ', 1 "fluorescent lamp 1
2,2 'arc tube
3a, 3b electrode
4 Shading film

Claims (6)

An arc tube enclosing a discharge medium containing at least argon therein to form a phosphor coating on an inner surface, and an electrode provided at both ends of the arc tube, wavelength 3 nm or more and, following 5 nm The light emitting tube is provided with a light blocking means for preventing all light from entering the arc tube from the outside and transmitting all light having a wavelength of less than 300 nm and all light having a wavelength of more than 500 nm. Fluorescent lamp. 2. The fluorescent lamp according to claim 1, wherein the light shielding means comprises a light shielding film formed on a surface of the arc tube. 3. The fluorescent lamp according to claim 2, wherein the light shielding film is formed at least on the surface of the arc tube in the vicinity of the electrode that causes an increase in starting voltage due to incidence of light. A plurality of fluorescent lamps each having an arc tube in which a phosphor film is formed on the inner surface and a discharge medium containing at least argon inside is enclosed, and electrodes respectively provided on both ends of the arc tube; and a mounted fixture body, the wavelength of the light emitted from the respective fluorescent lamps to the other fluorescent lamps 3 nm or more and all wavelengths of less than 300nm with all light 5 nm or less to shield A lighting fixture characterized in that the fixture body is provided with a light shielding means for transmitting light and all light having a wavelength exceeding 500 nm . It said shielding means has a wavelength of 3 nm or more and translucent wavelength and having a light shielding property with respect to all light 5 nm or less with respect to all the light all light and wavelength of less than 300nm exceeds 500nm 5. The lighting fixture according to claim 4, wherein the lighting fixture comprises a light-shielding member disposed between adjacent fluorescent lamps. 6. The lighting apparatus according to claim 5, wherein the light shielding member is disposed on the surface of the arc tube so as to shield at least a portion in the vicinity of the electrode that causes an increase in starting voltage due to incidence of light.

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