JP2013211274A - Method of manufacturing fluorescent lamp, fluorescent lamp, electric bulb type fluorescent lamp, and luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a phosphor layer film thickness of a light emission tube portion between both electrodes which serves an important role for fluorescent lamp light emission efficiency so that the whole luminous flux is 80% or more of the whole luminous flux at an optimum film thickness (25 μm).SOLUTION: A fluorescent lamp that uses as a light emission tube a glass tube for a spiral light emission tube of a double spiral type called a full spiral which has uniform revolution up to the end or a half spiral having a linear portion extending in the opposite direction to a revolution portion in a revolution axis direction from a revolution end is characterized in that a phosphor layer film thickness of a light emission tube portion surrounding at least between both electrodes is 10 μm or more and 90 μm or less.

Description

  The present invention relates to a phosphor coating method, a fluorescent lamp, a bulb-type fluorescent lamp, and an illumination device.

  A fluorescent lamp consists of a glass tube with an inner wall coated with a fluorescent material, and electrodes (filaments) attached to both ends of the glass tube. After the vacuum inside the glass tube is evacuated, a small amount of gas such as mercury and argon is used. Is enclosed. An electron emitting material is applied to the electrode. Mercury generates ultraviolet light. Argon gas also makes it easier to start discharge. Furthermore, the electron emitting material emits thermal electrons and maintains the discharge.

  In the fluorescent lamp, ultraviolet rays are generated by the discharge between the electrodes, and changes to visible light when the fluorescent material (phosphor layer) applied in the glass tube hits the ultraviolet rays.

  The fluorescent material (phosphor layer) formed on the inner surface of the glass tube is formed by being fired after being applied as a phosphor suspension.

  In recent years, light bulb-type fluorescent lamps have been reduced in size to the extent equivalent to general incandescent light bulbs, and the demand for replacing light sources of general incandescent light bulbs with light bulb-type fluorescent lamps has been promoted.

  As an example of the bulb-type fluorescent lamp, a fluorescent lamp is proposed that has a longer discharge path by bending the arc tube in a spiral shape (see, for example, Patent Document 1).

  Further, for the purpose of providing an arc tube capable of improving the lower luminance by effectively using visible light excited from a phosphor by ultraviolet rays, a bulb-type fluorescent lamp having the following configuration has been proposed. . That is, this light bulb-type fluorescent lamp includes an arc tube in which a fluorescent film is applied in a glass tube that is curved in a double spiral shape. This arc tube has a turning part that turns twice around the turning axis A, and a folded part that connects the two turning parts at the top. In each cross section of the glass tube, the fluorescent film applied to the wall surface on the end side of the glass tube in the direction parallel to the turning axis A is parallel to the turning axis A on the wall surface on the folded portion side. It is thicker than the applied fluorescent film (see, for example, Patent Document 2).

  Such a method of applying a phosphor to a double spiral glass tube is performed as follows. For example, the phosphor suspension is injected into the inside from the opening of the glass tube and applied to the inner surface. Next, the glass tube is held in such a position that the opening is downward, and the phosphor suspension is caused to flow out and drop from the opening. Finally, the glass tube is dried to form a phosphor film layer.

  The coating amount of the phosphor suspension on the inner surface of the glass tube is desirably uniform. If the thickness of the phosphor layer is not uniform, the conversion efficiency of ultraviolet rays generated inside the glass tube into visible light becomes insufficient in the thin portion of the phosphor layer. Further, in a portion where the phosphor layer is thick, light is blocked by the formed phosphor layer, and it becomes difficult to emit it to the outside of the glass tube, resulting in unevenness of the light.

JP 2003-263972 A JP 2004-186147 A

  However, in the phosphor coating method on the double spiral glass tube, there is a tendency that the coating amount in the entire glass tube becomes non-uniform. That is, the amount of application decreases as it approaches the folded portion (opposite side of the opening), and the amount of application increases as it approaches the opening.

  In addition, there is a tendency that the coating amount in the cross section of the swivel portion becomes non-uniform. In other words, the amount of application in the cross section of the swirling portion that is swiveling decreases on the folded portion side (opposite side of the opening portion) and increases on the opposite opening portion side.

  The present invention has been made to solve the above-described problems, and provides a fluorescent lamp manufacturing method, a fluorescent lamp, and a bulb-type fluorescent lamp capable of controlling the non-uniformity of the coating amount of the phosphor suspension. A lamp and a lighting device are provided.

The fluorescent lamp according to the present invention is for a double spiral spiral arc tube called a full spiral with uniform turning to the end or a half spiral having a straight part extending in the direction of the turning axis from the turning end in the direction opposite to the turning portion. In a fluorescent lamp using a glass tube as an arc tube,
The phosphor layer thickness of the arc tube portion surrounding at least both electrodes is 10 μm or more and 90 μm or less.

  The fluorescent lamp according to the present invention has improved luminous efficiency.

FIG. 5 shows the first embodiment, and is an external view of a bulb-type fluorescent lamp 1. FIG. 3 is a diagram illustrating the first embodiment, and is a lamp structure diagram illustrating the inside of the light bulb-type fluorescent lamp 1; FIG. 3 shows the first embodiment and is a front view of a double spiral arc tube 2. FIG. 5 shows the first embodiment, and shows a method of applying a phosphor to the inner surface of a glass tube of a double spiral arc tube 2. In the figure which shows Embodiment 1, the state which inject | poured the fluorescent substance suspension 13 into the surrounding part of the 1st turn | start from the turning termination | terminus surface into the pipe | tube inner peripheral surface and below the turning part termination | terminus surface. FIG. In the figure which shows Embodiment 1, the state which inject | poured the fluorescent substance suspension 13 into the surrounding part of the 1st turn | start from the turning termination | terminus surface into the pipe | tube inner peripheral surface and below the turning part termination | terminus surface. FIG. FIG. 5 shows the first embodiment, and shows the relationship between the phosphor layer thickness of the fluorescent lamp and the total luminous flux. FIG. 5 shows the first embodiment, and is a diagram in which the phosphor layer film thickness of each stage of the double spiral arc tube 2 is compared between the example and the conventional example. The schematic diagram which shows the phosphor layer thickness distribution of an ideal phosphor layer, and the phosphor layer thickness distribution by the conventional coating method. The figure which shows Embodiment 1 and is a figure which shows the luminous flux maintenance factor after 2000 hours lighting at the time of lighting by the measuring method and measurement conditions prescribed | regulated by JISC7620-2.

Embodiment 1 FIG.
FIGS. 1 and 2 are diagrams showing the first embodiment. FIG. 1 is an external view of the light bulb-type fluorescent lamp 1, and FIG.

  As shown in the outline drawing of FIG. 1, the bulb-type fluorescent lamp 1 includes an outer tube glove 6 and a cover 4 having a base 5 to form an outer shell (envelope).

  In addition, as shown in FIG. 2, a double spiral arc tube 2 in a bulb-type fluorescent lamp 1 envelope (outer tube globe 6 and cover 4) is a high frequency lamp that lights the double spiral arc tube 2 A circuit 3 is provided. The double helix arc tube 2 includes electrodes 7 made of filaments at both ends.

  The bulb-type fluorescent lamp 1 using the double spiral arc tube 2 has an advantage that the distance between the electrodes in the arc tube can be made longer in a fixed space than the arc tube in which a plurality of U-shaped glass tubes are combined. Further, by narrowing the glass tube constituting the arc tube and narrowing the interval between adjacent glass tubes in the direction of the pivot axis to about 1 mm, the arc tube itself is swung around the pivot axis without extending. The number of turns can be increased. Thereby, the distance between the electrodes in the arc tube can be increased, and the brightness equivalent to that of the incandescent bulb can be obtained.

  The bulb-type fluorescent lamp 1 using the double helix arc tube 2 is, for example, a bulb-type fluorescent lamp EFA15 / 12 which is an alternative to the general bulb 60W.

  The double helix arc tube 2 is a vertical helix having a predetermined height in a double helix, and has a portion that is swung with a constant diameter.

  The double spiral arc tube 2 has a double spiral shape called a full spiral with uniform turning to the end, or a half spiral having a straight portion extending in the direction of the turning axis from the turning end in the direction opposite to the turning portion. To do.

  There is an exhaust pipe (not shown) for exhausting air from the inside of the double spiral arc tube 2 from one end of the double spiral arc tube 2.

  A mercury emission source (not shown) is provided in the exhaust pipe. Mercury emission sources are liquid mercury or mercury alloys having a mercury vapor pressure equivalent to liquid mercury, or mercury alloys whose mercury vapor pressure is adjusted to be lower than that of liquid mercury, usually called mercury amalgam. Further, an amalgam form mainly containing In, In-Bi-Hg, or an amalgam form mainly containing Pb or Pb-Bi-Sn-Hg may be used.

  The circuit efficiency of the high-frequency lighting circuit 3 (electronic ballast) is 90% or more.

  FIG. 3 shows the first embodiment and is a front view of the double spiral arc tube 2. The double helix arc tube 2 includes a glass tube 2a and an electrode 7 (see FIG. 1) made of a filament.

  The glass tube 2 a has a double spiral turning unit 10. The swivel unit 10 has a first swivel unit 10a that swivels around the spiral swivel central axis X to one end 11 and a turn-up unit 8 (top) as a starting point. It comprises a second turning portion 10b that turns around the turning center axis X to the other end portion 12.

  The glass tube 2a is soft glass of sodaram glass. In the glass tube 2a, about 3.5 mg of mercury and about 500 Pa of argon as a buffering rare gas are sealed at a normal temperature pressure.

  On the inner surface of the glass tube 2a, a phosphor layer (not shown) including a phosphor that converts ultraviolet light into visible light is formed.

Next, the phosphor coating method for the glass tube 2a will be described. The double helix arc tube 2 is manufactured by the following process.
(1) forming a straight glass tube into a double helix;
(2) A step of applying a phosphor to the inner surface of the glass tube to form a phosphor layer;
(3) Processes such as electrode sealing, noble gas, mercury sealing, etc.

FIG. 4 is a diagram showing the first embodiment, and is a diagram showing a method of applying a phosphor to the inner surface of the glass tube of the double spiral arc tube 2. Hereinafter, with reference to FIG. 4, a step of applying a phosphor on the inner surface of the glass tube to form a phosphor layer (phosphor coating method) will be described.
(A) Pouring step: The turning center axis X is set substantially horizontally, the end of the first turning portion 10a of one glass tube 2a faces upward, and the turning end surface is substantially horizontal. From the horizontal turning end surface facing upward, the phosphor suspension 13 is injected into the circulation portion of the first turn starting from the turning end surface at a position equal to or higher than the inner peripheral surface of the tube and below the end surface of the turning portion. To do.

  5 and 6 are diagrams showing the first embodiment. FIG. 5 shows the phosphor in the first round circuit where the turning end surface is the starting point, and the liquid amount is not less than the inner peripheral surface of the pipe and not more than the end surface of the turning part. FIG. 6 is a side view showing a state in which the suspension 13 is injected, and FIG. 6 shows a phosphor suspension in the first round of circulation starting from the swivel end surface, and the liquid volume is greater than the inner peripheral surface of the tube and less than the end surface of the swivel portion. It is a front view which shows the state which inject | poured the liquid 13. FIG.

  In the injection step, the reason for injecting the phosphor suspension 13 in the first circulation portion starting from the turning end surface is greater than or equal to the inner peripheral surface of the tube and below the turning portion end surface (phosphor suspension) The reason why the injection amount of 13 is prescribed) is that if the injection amount is larger than the horizontal at the end of the swivel portion, the phosphor suspension 13 overflows from the opening 14a to the outside of the glass tube 2a. This is because the liquid 13 does not come into contact with the inner peripheral surface of the tube, so that unpainted portions are generated inside the spiral (see FIGS. 5 and 6).

(B) Coating step: Injection is performed by rotating the double helix-shaped glass tube 2a about the spiral rotation center axis X so that the injected phosphor suspension 13 moves from the opening 14a side to the opposite side. The phosphor suspension 13 is applied while moving. The rotation direction of the glass tube 2a is a direction in which the position of the terminal end of the first turning unit 10a is raised by the rotation.

(C) Inversion step: After the phosphor suspension 13 reaches the tip of the center of the swivel part ((turning part 8 (top))), the direction of rotation of the double spiral arc tube 2 is reversed and rotated, Furthermore, the phosphor suspension 13 is sent to the other second swivel unit 10b.

(D) Outflow process: Further, after the application of the phosphor suspension 13 to the entire inside of the glass tube 2a is completed, the rotation of the double helical arc tube 2 is continued and the excess phosphor suspension 13 is caused to flow out. .

(E) Drying step: Thereafter, the rotation of the double helix-shaped glass tube 2a is stopped, the relative positional relationship between the opening 14a and the inner blow air blowing nozzle for drying inside the tube is made constant, and hot air is sent from the opening 14 to the glass tube. The phosphor layer is fed into 2a and dried.

  In addition, this fluorescent substance coating method is implemented by the method shown below in a production line. That is, if the rotation that rotates around the central axis of the double helix glass tube is rotation, it has one disk-shaped revolution surface with a plurality of rotation axes, and the rotation axis is installed radially from the center of the revolution surface. At least the double spiral glass tube installed on each rotation shaft circulates a part of the revolution surface to finish the coating and drying process.

  As another method, if the rotation that rotates around the central axis of the double helix glass tube is self-rotating, it has a track-like revolving surface with a plurality of revolving shafts, and the revolving shaft is outside the revolving surface. There is also a method in which the double spiral glass tube installed and installed at least on each rotation shaft circulates a part of the revolution surface to finish the coating and drying process.

  Furthermore, it has a linear drying device that rotates about the central axis of the double helix glass tube and has a plurality of rotation axes, and at least the double helix glass tube installed on each rotation axis has a drying device. The coating and drying process is completed by the end of the straight line.

  The opening 14a at the end of the double spiral glass tube 2a is a spiral extension.

  Further, the opening 14a at the end of the double spiral glass tube 2a may be bent out of the spiral in the direction of the spiral turning central axis X.

  The phosphor coating method described above can also be used for fluorescent lamps other than bulb-type fluorescent lamps. The phosphor layer obtained by the above-described phosphor coating method has a uniform film thickness and does not cause unevenness in the lamp light.

  FIG. 7 is a diagram showing the first embodiment, and is a diagram showing the relationship between the phosphor layer thickness of the fluorescent lamp and the total luminous flux. In order to increase the luminous efficiency of the fluorescent lamp, it is important to set the film thickness of the phosphor layer to an optimum value. The optimum value of the film thickness of the phosphor layer depends on the particle size and particle size distribution of the phosphor and the attributes of each phosphor to be mixed, but is about 25 μm (see FIG. 7).

  FIG. 8 is a diagram showing the first embodiment, in which the coating film thickness of each stage of the double spiral arc tube 2 is compared between the example and the conventional example, and FIG. 9 shows the ideal phosphor layer thickness distribution. It is a schematic diagram which shows the fluorescent substance layer film thickness distribution by the conventional coating method. The phosphor layer thickness on the inner surface of the arc tube between the two electrodes, which are the light emitting part of the fluorescent lamp, is desired to be about 25 μm everywhere (ideal phosphor layer in FIG. 9). However, when the phosphor layer is formed by applying and drying the phosphor with the phosphor suspension 13, the phosphor suspension 13 moves by gravity before drying, and the top is thin and the bottom is thick. Is out of the optimum value in many parts (see FIG. 8). Conventionally, the phosphor suspension 13 is injected with the opening 14a on the top and the spiral pivot center axis X being vertical, and is inverted to allow the excess phosphor suspension 13 to be dropped and discharged from that position in the drying furnace. The warm air flowed into the tube and dried, resulting in a film thickness distribution as shown in FIGS. The phosphor layer thickness distribution by the conventional coating method is that the phosphor layer drops due to gravity, so the top is thin and the luminous efficiency is poor, and the bottom is accumulated in the tub, making the phosphor layer extremely thick. The efficiency of the portion is lowered despite the fact that many expensive phosphors are distributed.

  The objective is to control the phosphor layer thickness of the arc tube portion between the electrodes, which plays an important role in the luminous efficiency of the fluorescent lamp, so that the total luminous flux is 80% or more of the total luminous flux with the optimum film thickness (25 μm). It was. From FIG. 7, it can be seen that the phosphor layer thickness of the arc tube portion between both electrodes may be 10 μm or more and 90 μm or less.

  A soda glass tube with a tube outer diameter of 9 mm and a tube inner diameter of 7 mm, a full spiral arc tube with a circular outer diameter of 36 mm and a swivel number of 4.5 times, and a discharge tube with a discharge distance of 400 mm between electrodes is formed. After the formation, the arc tube produced by the manufacturing method of the present embodiment using the same phosphor suspension as in the past (the film thickness of each part was within the range of 10 to 90 μm as shown in FIG. ) And the conventional arc tube produced by the vertical dry coating method were used as a lamp as EFA15EL / 12 defined in JIS C 7651, and then compared. As a result, the fluorescent lamp using this coating method achieved an improvement in luminous efficiency of about 5% compared to the conventional product (see FIG. 8).

  FIG. 10 is a diagram illustrating the first embodiment, and is a diagram illustrating the luminous flux maintenance factor after 2000 hours of lighting when the lighting is performed according to the measurement method and measurement conditions defined in JIS C 7620-2. Further, when these lamps were subjected to a life test in accordance with JIS C 7620-2, it was found that the luminous flux maintenance factor of the bulb-type fluorescent lamp 1 (example) of the present embodiment was also improved as an unexpected effect. This is reproducible and experimentally confirmed to be an essential effect. Although it is considered that the influence of sodium precipitation in the phosphor layer thin film portion has decreased and the influence of impure gas occlusion in the phosphor layer thick film portion has decreased, it has not been clearly analyzed.

  By using a fluorescent lamp or a bulb-type fluorescent lamp that uses the above-described phosphor coating method for the lighting device, an excellent lighting device that does not cause unevenness in the light of the lamp can be obtained.

  DESCRIPTION OF SYMBOLS 1 Bulb-type fluorescent lamp, 2 Double spiral luminous tube, 2a Glass tube, 3 High frequency lighting circuit, 4 Cover, 5 base, 6 Outer tube glove, 7 Electrode, 8 Folding part, 10 Turning part, 10a 1st turning Part, 10b 2nd turning part, 11 edge part, 12 edge part, 13 fluorescent substance suspension, 14a opening part.

Claims (4)

A glass tube for a double spiral spiral arc tube called a full spiral with uniform turning to the end or a half spiral with a straight part extending in the direction of the axis of rotation from the end of rotation in the direction opposite to the turning part is used as the arc tube. In fluorescent lamps,
A fluorescent lamp characterized in that a phosphor layer thickness of an arc tube portion surrounding at least both electrodes is 10 μm or more and 90 μm or less. A glass tube for a double spiral spiral arc tube called a full spiral with uniform turning to the end or a half spiral with a straight portion extending in the direction of the axis of rotation from the end of the rotation in the direction opposite to the turning part is used as the arc tube. In a light bulb shaped fluorescent lamp equipped with a lighting circuit for lighting this arc tube,
A light-bulb fluorescent lamp characterized in that at least the phosphor layer thickness of the arc tube portion surrounding both electrodes is 10 μm or more and 90 μm or less.   An illuminating device using the fluorescent lamp according to claim 1 or the bulb-type fluorescent lamp according to claim 2. A glass tube for a double spiral spiral arc tube called a full spiral with uniform turning to the end or a half spiral with a straight part extending in the direction of the axis of rotation from the end of rotation in the direction opposite to the turning part is used as the arc tube. In the method of manufacturing a fluorescent lamp,
A method of manufacturing a fluorescent lamp, wherein the thickness of a fluorescent material layer of an arc tube portion surrounding at least both electrodes is 10 μm or more and 90 μm or less.

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