JPH0714549U - Electrodeless fluorescent lamp - Google Patents

Abstract

(57) [Summary] [Object] To prevent scattering of a fluorescent film due to encapsulation of argon gas in an electrodeless fluorescent lamp equipped with a valve having an open tubular inner tube. A light emitting bulb (5) having an outer bulb (1) and an open tubular inner tube (2) integrally formed in the center of the outer bulb is provided, and the inner wall of the outer bulb (1) of the light emitting bulb (5) and the surface of the inner tube (2). In the electrodeless fluorescent lamp in which the phosphor 6 is applied to the outer bulb 1, the outer bulb 1 is filled with mercury and argon gas, and the high frequency output coil is arranged inside the inner bulb 2, the open tubular inner bulb 2 A tapered concave portion 3 is formed at the closed end of the concave portion 3, and an exhaust pipe 4 is connected to the bottom portion of the concave portion 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electrodeless fluorescent lamp having a high-frequency output coil inside an open tubular inner tube provided inside an outer bulb.

[0002]

[Prior art]

 There are various types of electrodeless discharge lamps that utilize high-frequency electrodeless discharge, which have been researched and developed in recent years. Among electrodeless fluorescent lamps, the structure shown in Fig. 2 is known. ing. In FIG. 2, reference numeral 101 denotes an outer sphere, which is integrally provided with an open cylindrical inner tube 102 at the center thereof, and an exhaust pipe 103 is provided at a closed end portion of the inner tube 102 to form a fluorescent bulb 104. The phosphor 105 is applied to the inner surface of the outer bulb 101 and the surface of the inner tube 102 (on the discharge space side of the bulb 104), and mercury and argon gas are enclosed in the discharge space of the bulb 104. A high frequency output coil 106 is inserted and arranged inside the inner tube 102, and a high frequency power of 13.56 MHz is supplied to the high frequency output coil 106 from a high frequency generating power source 107.

In the electrodeless fluorescent lamp configured as described above, a high frequency electromagnetic field is generated inside the bulb 104 by turning on the power and supplying high frequency power from the high frequency generating power source 107 to the high frequency output coil 106. When applied, mercury is excited to generate ultraviolet rays, and the ultraviolet rays stimulate phosphors 105 to emit visible light.

[0004]

[Problems to be solved by the device]

 By the way, when manufacturing the electrodeless fluorescent lamp having such a structure, after applying the phosphor 105 to the inner wall of the outer bulb 101 of the bulb 104 and the surface of the inner tube 102, the interior of the bulb 104 is evacuated to remove mercury and mercury. In the process of filling the argon gas, a work called washing is performed to make the inside of the valve 104 high vacuum in a short time. This washing work is to attach the exhaust pipe 103 of the valve 104 to the exhaust machine, exhaust the air inside the valve 104 with a vacuum pump, stop the exhaust operation after several tens of seconds and fill it with argon gas, and then perform the exhaust operation again. It is the work to do.

By performing the washing operation once or more, the exhausting process can be completed in a shorter time than performing continuous exhausting, and such a washing process is well known, and the exhausting process is performed in a lamp or the like. It is often used.

However, if the exhaust gas is exhausted and the argon gas is filled through the exhaust pipe 103 with the bulb shape of the conventional electrodeless fluorescent lamp, the filling pressure of the argon gas filled from the outlet of the thin exhaust pipe 103 causes. In FIG. 3, there occurs a phenomenon that the phosphor 105 at a portion facing the outlet of the exhaust pipe 103 of the outer sphere 101 blows off and scatters. In order to prevent this, it is necessary to lower the argon gas filling pressure, which causes a problem of lowering the production rate.

The present invention has been made to solve the above-mentioned problems in the conventional electrodeless fluorescent lamp, and it is possible to prevent scattering of the fluorescent film without lowering the argon gas filling pressure during the washing operation. It aims at providing the electrodeless fluorescent lamp which was made into.

[0008]

[Means and Actions for Solving the Problems]

 In order to solve the above problems, the present invention provides an outer sphere, an open tubular inner pipe formed at the center of the outer sphere, and an exhaust pipe provided at a closed end of the open tubular inner pipe. A light emitting bulb having a light emitting bulb, a fluorescent substance is applied and formed on the inner wall of the outer bulb of the light emitting bulb and the surface of the inner tube, and a filling gas is enclosed in the light emitting bulb; and a high frequency output coil is arranged inside the inner tube. In the electrodeless fluorescent lamp as described above, a tapered recess is formed at the closed end of the open tubular inner tube, and an exhaust pipe is connected to the bottom of the recess.

In the electrodeless fluorescent lamp configured as described above, since the exhaust pipe is connected to the bottom of the tapered concave portion provided at the closed end of the open tubular inner pipe, the exhaust pipe is connected to the outlet of the exhaust pipe during the washing operation. The enclosed pressure of the argon gas is reduced by the tapered concave portion and is injected toward the inner wall portion of the outer sphere. Therefore, it is possible to effectively prevent scattering of the phosphor formed on the inner wall of the outer sphere without lowering the filling pressure of the argon gas filled from the exhaust pipe, and to reduce the production rate due to the reduction of the filling pressure. Can be stopped.

[0010]

【Example】

 Next, examples will be described. FIG. 1 is a schematic sectional view showing a bulb portion of an embodiment of the electrodeless fluorescent lamp according to the present invention. In FIG. 1, reference numeral 1 is an outer sphere, and an open cylindrical inner tube 2 is integrally formed at the center of the outer sphere 1, and a funnel-shaped or tapered shape is formed at a closed end of the inner tube 2. A recess 3 is formed, and an exhaust pipe 4 is connected to the bottom of the tapered recess 3 to form a light emitting bulb 5. Then, the phosphor 6 is applied to the inner wall surface of the outer bulb 1 and the surface of the inner tube 2 (on the discharge space side of the bulb 5), and mercury and argon gas are enclosed in the bulb 5 to form an electrodeless fluorescent lamp. is doing. Further, as in the conventional case, a high-frequency output coil (not shown) is inserted and arranged inside the inner tube 2, and high-frequency power is supplied to turn on the light.

In the present invention, as described above, since the tapered recessed portion 3 is provided at the closed end portion of the inner pipe 2 and the exhaust pipe 4 is connected to the bottom portion thereof, during the washing operation in the exhaust process, When the argon gas is filled through the exhaust pipe 4, the gas ejection passage expands from the outlet of the exhaust pipe 4 toward the tapered recessed portion 3, so that the filled gas pressure is reduced. Therefore, the filling pressure of the argon gas injected into the facing portion A of the exhaust pipe 4 of the outer bulb 1 is significantly reduced, and there is no possibility that the phosphor 5 will scatter in the portion A. Therefore, it is not necessary to reduce the filling pressure of the argon gas, and it is possible to prevent the production rate from decreasing. Even when the washing operation is omitted, the same effect can be obtained when argon gas is filled as the filling gas.

Further, when the position of the high-frequency output coil inserted and arranged inside the inner pipe 2 is set to the same position as the conventional one, the distance from the outlet of the exhaust pipe 4 to the portion A of the outer bulb 1 is further increased. Therefore, the gas injection pressure in the outer sphere portion A is further reduced. Further, the connection position of the exhaust pipe 4 becomes closer to the center position of the outer sphere, and it becomes possible to make it shorter than the conventional one.

[0013]

[Effect of device]

 As described above based on the embodiments, according to the present invention, it is possible to provide an electrodeless fluorescent lamp that can effectively prevent the scattering of the phosphor without lowering the filling pressure of the argon gas in the exhaust process. it can.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a structure of a bulb portion of an embodiment of an electrodeless fluorescent lamp according to the present invention.

FIG. 2 is a schematic diagram showing a configuration example of a conventional electrodeless fluorescent lamp.

FIG. 3 is a diagram for explaining a problem in the electrodeless fluorescent lamp shown in FIG.

[Explanation of symbols]

 1 Outer sphere 2 Open tubular inner tube 3 Tapered recess 4 Exhaust pipe 5 Luminescent bulb 6 Phosphor

Claims (1)

[Scope of utility model registration request] 1. A light emission valve having an outer bulb, an open tubular inner tube formed in a central portion of the outer bulb, and an exhaust tube provided at a closed end portion of the open tubular inner tube. An electrodeless fluorescent lamp in which a phosphor is applied and formed on the inner wall of the outer bulb of the bulb and the surface of the inner tube, a filling gas is enclosed in the light emitting bulb, and a high-frequency output coil is arranged inside the inner tube. An electrodeless fluorescent lamp characterized in that a tapered recess is formed at the closed end of an open tubular inner tube, and an exhaust pipe is connected to the bottom of the recess.