JPH0393195A - Rare gas discharge fluorescent lamp device - Google Patents

Abstract

PURPOSE:To obtain a fluorescent lamp with high efficiency and high intensity by providing a serial circuit with a current limiting element and a pulse signal source applying the specific pulse signal to a switching element. CONSTITUTION:A serial circuit constituted of a DC power source 12 and a current limiting element 13 is connected between the anode 3a of a rare gas discharge fluorescent lamp 10 and one end of a cathode filament coil 3b, and a switching element 15 is connected between the anode 3a and the other end of the cathode filament coil 3b respectively. The fluorescent lamp 10 is discharged when the switching element 15 is opened by the pulse signal from a pulse signal source 16. The discharge period of the fluorescent lamp 10 by the opening of the switching element 15 is set to 150musec or below at the rate of 5-70% in one cycle for the xenon gas or krypton gas-sealed fluorescent lamp 10. The high-intensity and high-efficiency fluorescent lamp 10 is obtained by the pulse-shaped discharging.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a rare gas discharge fluorescent lamp device used in information equipment such as facsimile machines, copying machines, and image readers. [Conventional technology] In recent years, with the advancement of the information society, information terminal devices such as facsimiles, copiers, and image readers have become more sophisticated.
This market is rapidly expanding. In developing these increasingly high-performance information devices, high-performance light source units are required as key devices. Conventionally, halogen lamps and fluorescent lamps have often been used as lamps for this light source unit. but,
Due to the inefficiency of halogen lamps, more efficient fluorescent lamps have been mainly used in recent years. However, although fluorescent lamps have high efficiency, they use discharge of mercury vapor for light emission, so there is a problem that characteristics such as light output change depending on temperature. It was used to control the temperature by attaching a However, due to the diversification of usage locations and the increasing performance of equipment, there has been a strong desire to develop fluorescent lamps with stable characteristics. Against this background, rare gas discharge fluorescent lamps have been developed as light sources for information equipment, which utilize light emission from rare gas discharge without any change in temperature characteristics. 17 and 18 show a conventional rare gas discharge fluorescent lamp device disclosed in, for example, Japanese Patent Laid-Open No. 63-58752, and FIG. 17 shows a cross section of the rare gas discharge fluorescent lamp and the device. Figure 18, which is a block diagram showing the overall structure, is a longitudinal sectional view of the lamp. In the figure, (1) is a bulb in the shape of an elongated hollow rod, and is made of quartz, hard or soft glass. The inner surface of this bulb (1) is coated with a phosphor coating (2). In addition, a rare gas consisting of at least one of xenon, krypton, argon, neon, helium, etc. is sealed inside the valve (1). Inside the bulb (1), a pair of internal electrodes (3a) and (3b) with mutually different polarities are provided at both ends. These internal electrodes (3a) and (3b) are connected to a lead m (4) that passes through the end wall of the bulb (1) in an airtight manner. Further, a band-shaped external electrode (5) is provided on the outer surface of the side wall of the bulb (1) along the axial direction. The internal electrodes (3a) and (3b) are connected to a high frequency inverter (8) as a high frequency power generator via lead wires (4).
), and this high frequency inverter (8) is connected to a DC power supply (9). The external electrode (5) is connected to the high frequency inverter (8) so as to have the same polarity as one of the internal electrodes (3a). Next, we will explain the operation. In a rare gas discharge fluorescent lamp device having such a structure, when high frequency power is applied between the internal electrodes (3a) and (3b) through the high frequency inverter (8), the voltage between these internal electrodes (3a) and (3b) increases. A glow discharge occurs. These glow discharges excite the rare gas inside the bulb (1) and emit ultraviolet light unique to rare gases. This ultraviolet light excites the phosphor coating (2) formed on the inner surface of the bulb (1), from which visible light is emitted and emitted to the outside of the bulb (1).

In addition, as an example of other rare gas discharge fluorescent lamps, JP-A-63
There is one shown in Publication No.-248050. This lamp uses a hot cathode electrode as disclosed in, for example, Japanese Patent Publication No. 63-29931, in order to improve the drawback of the high starting voltage of cold cathode rare gas discharge lamps. This rare gas discharge fluorescent lamp can increase its output by increasing the power load. However, compared to mercury vapor fluorescent lamps, significantly lower efficiency and light output can be achieved. Additionally, hot cathode lamps require a power source to heat the filament coil of the electrode. [Problems to be Solved by the Invention] As described above, conventional rare gas discharge fluorescent lamp devices cause the phosphor to emit light using ultraviolet rays generated by rare gas discharge, and therefore have lower efficiency than fluorescent lamps using mercury. ,
It was difficult to obtain sufficient brightness, and improvements in efficiency were desired. This invention was made to solve the above-mentioned problems, and its purpose is to obtain a rare gas discharge fluorescent lamp device with high efficiency and high brightness. [Means for Solving the Problems] A rare gas discharge fluorescent lamp device according to the present invention has a phosphor layer formed on the inner surface and a pair of electrodes at both ends, each of which is a cathode and anode, and at least the cathode is a filament coil. A rare gas discharge fluorescent lamp comprising a glass bulb filled with xenon gas or krypton gas, a DC power source and a current limiter connected between the anode of the rare gas discharge fluorescent lamp and one end of the cathode filament coil. a switching element connected between the anode of the rare gas discharge fluorescent lamp and the other end of the cathode filament coil; It is equipped with a pulse signal source that applies a pulse signal that is open for a period of 70% or less and 150 μsec or less in one cycle. In addition, in the rare gas discharge fluorescent lamp device according to another aspect of the present invention, the gas sealed in the bulb is argon gas, and the period during which the switching element is opened by the pulse signal from the pulse signal source is set to one cycle. The ratio is 5% or more and 80% or less, and the duration is 150 μsec or less in one cycle. [Function] In the rare gas discharge fluorescent lamp device of the present invention, a series circuit consisting of a DC power supply and a current limiting element is connected between the anode of the rare gas discharge fluorescent lamp and one end of the cathode filament coil. Since each switching element is connected between the other end of the coil, the voltage applied to the rare gas discharge fluorescent lamp becomes zero during the closing period by the pulse signal from the pulse signal source of this switching element, and the rare gas discharge fluorescent lamp becomes zero. Discharge fluorescent lamps do not discharge, but the cathode filament coil is preheated by the current flowing to the switching element through the current limiting element, and rare gas discharge fluorescent lamps discharge when the switching element is opened. When the discharge period of the rare gas discharge fluorescent lamp due to opening of this switching element is 5% or more and 70% or less of one cycle for a rare gas discharge fluorescent lamp filled with xenon gas or krypton gas, the discharge period is one cycle. For a rare gas discharge fluorescent lamp filled with argon gas, the ratio to one cycle is 5% or more and 80% or less and 150 μsec or less in one cycle, so this pulsed discharge causes light emission. The probability that the molecules of the filled gas are excited at an energy level at which a large amount of the resonant ultraviolet radiation of the contributing gas is emitted increases, increasing the light output and efficiency of the lamp, and causing wear and tear on the electrodes due to the pulsed discharge. is suppressed. [Embodiment of the Invention] An embodiment of the invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of an embodiment of the present invention. In the figure, (10) is a rare gas discharge fluorescent lamp with a diameter of 15.5 mm.
■ Ugly, a phosphor film is formed on almost the entire inner surface of the straight cylindrical glass bulb (1L) with a length of 300 mm, and inside the bulb (11) there is xenon gas, krypton gas, or It is filled with argon gas. Valve (l1)
At both ends of the , there are electrodes (
3a) and (3b) are sealed. Valve (1l
) An aluminum plate of 1113 am is glued along the entire length of the lamp as a starting auxiliary conductor.
(12) is a DC power supply, (13) is a current limiting element which is a resistor, and this DC power supply (12) and current limiting element (13)
The series circuit (l4) with the anode (3a) of the lamp (10)
and one end of the cathode filament coil (3b). (15) is a switching element such as a transistor, which is connected between the anode (3a) of the lamp (lO) and the other end of the cathode filament coil (3b). (16) is a pulse signal source that generates a pulse signal for opening and closing the switching element (15).

Next, the operation will be explained. In the rare gas discharge fluorescent lamp device with the configuration shown in Figure 1, the DC voltage from the DC power source (12) passes through the lamp (10
) is applied between the anode (3a) and one end of the cathode filament coil (3b). However, since the switching element (15) is sent between the @ pole (3a) and the other end of the cathode filament coil (3b), the pulse signal source (
the switching element (l5) is closed for a period and period determined by the period and pulse width of the pulse signal from l6);
The voltage applied to the lamp (10) is cut off, and during this time current flows through the cathode filament coil (3b) to preheat it. Therefore, the voltage applied to the lamp becomes a DC pulse voltage, and the discharge inside the glass bulb (l1) also becomes a pulsed discharge with a rest period in the lamp current, and the cathode is preheated during this rest period. In the following, in the rare gas discharge fluorescent lamp device described above, the glass bulb (11) is filled with each gas such as xenon gas, krypton gas, or argon gas, and the lamp (10) is lit intermittently. 11> The relationship between the pressure of each gas sealed in the lamp, the ratio of current-on time during one cycle of the lamp (hereinafter referred to as intermittent ratio), and the current-on time during one cycle, lamp efficiency, starting voltage, and lamp life was experimentally determined. I will explain based on the results. Figure 2 shows the relationship between the filled gas pressure and the lamp efficiency when xenon gas is filled.The lamp efficiency is calculated from the luminance divided by the electric power. In Figure 2, (a) shows the case of square wave DC pulse lighting with an intermittent ratio of 60%, and (opening) shows the case of normal high frequency AC lighting (sine wave), both values at a frequency of 20kHz and the same power. ,IQT
It can be seen that there is no significant difference in efficiency between pulsed lighting and AC lighting at fill pressures below 10 Torr, but at temperatures above 10 Torr, the efficiency during pulsed lighting exceeds the efficiency during AC lighting.
However, when the sealing pressure becomes about 70 Torr or more, the efficiency of the AC lamp increases, but the efficiency of the pulse lamp starts to decrease and approaches the value for AC lamp again at 200 to 300 Torr. Furthermore, Figure 3 shows the relationship between the filled gas pressure and the starting voltage when xenon gas is filled, and from this figure it can be seen that as the gas filled pressure increases, a very high voltage is required for starting. In particular, if the gas filling pressure is 200 Torr or more, the starting voltage will increase significantly, so it is desirable that the filling gas pressure is 200 Torr or less. Therefore, from Figures 2 and 3, the optimal gas filling pressure is 10To to perform pulse lighting, which is more efficient than high-frequency lighting and is practical at the starting voltage.
rr or more and 200τorr or less. In addition, the diameter is 8-15 to 15.5-1, and the length is 300++ a.
A large number of lamps were manufactured with a xenon gas filling pressure of 30 Torr, and the characteristics of the lamps were measured by varying the DC pulse lighting conditions. Figures 4 and 5 show the results. Figure 4 shows the relationship between the energization time and lamp efficiency during one cycle of the DC pulse, and the non-energization time is 100 μs.
The case where ec is constant is shown. From this figure, it can be seen that the shorter the pulse energization time, the better the efficiency, and the effect is particularly remarkable when the pulse energization time is 150 μsec or less. Figure 5 shows the relationship between lamp efficiency and pulse intermittency ratio during pulse lighting from 5KHz to 80KHz ((c)(ii)(e)). In addition, as a comparison value, 80 KHz from the commonly used 5 KHz
Efficiency values during KHz high frequency AC lighting (sine wave) are also shown ((e)(e)(e)). From Figure 5, we can see that DC lighting (intermittent ratio 100%) can be achieved by reducing the pulse intermittency ratio.
), and even when compared with AC lighting at the same frequency, it can be seen that the efficiency is significantly higher if the pulse intermittency ratio is set to 70% or less. Furthermore, we manufactured a number of lamps with diameters from 8mm to 15.5mm and xenon gas filling pressures from 10 Torr to 200 Torr, and conducted life tests on these lamps by varying the pulse intermittency ratio while keeping the lamp power constant. The results are shown in Figure 6. Here, the relative life is the ratio of the average life time when the lamp is lit at each intermittent ratio to the average life time when the lamp is lit at a predetermined intermittent ratio (for example, 40%).
The relationship between the pulse intermittency ratio and the relative lifespan is shown in Figure 6, as the pulse intermittency ratio decreases, up to 5%.
It can be seen that the relative life tends to decrease slightly, and at a small intermittency ratio of 5% or less, the life decreases rapidly. It is estimated that if it is less than 5%, the pulse peak current of the lamp will increase, causing rapid wear on the electrodes. Therefore, a pulse intermittency ratio of 5% or more is embarrassing when considering the lifespan. FIGS. 7 to 11 are characteristic diagrams showing the results of tests similar to the above-mentioned lamps filled with xenon gas for lamps (10) filled with krypton gas in the glass bulb (11). ．． From these test results, when krypton gas is filled, the optimal gas filling pressure is 1QTorr or more and 100Torr or less, the pulse energization time in one cycle is 150μsec or less, and the pulse intermittency ratio is preferably 5% or more and 70% or less. I understand that. Furthermore, Figures 12 to 16 show a lamp (10) in which argon gas is filled in a glass bulb (11). This is a characteristic diagram showing the results of a test run similar to that described above. Similarly, from these test results, when filling with argon gas, the optimal gas filling pressure is 10 Torr or more,
It can be seen that it is desirable that the pulse current is 100 Torr or less, the pulse energization time during one cycle is 150 μtsec or less, and the pulse intermittency ratio is 5% or more and 80% or less. All of the above embodiments use hot cathode lamps in which the cathode is a filament coil. Conventionally, hot cathode lamp lighting devices require a preheating power source to heat the cathode in addition to the lighting power source, but in this circuit shown in Figure 1, the voltage applied to the lamp is Because current flows through the filament coil of the cathode and heats it up. There is no need for a preheating power supply, and the structure of the device becomes simpler. [Effects of the Invention] As described above, according to the present invention, a phosphor layer is formed on the inner surface, and xenon is placed inside a glass bulb having a pair of electrodes at both ends, each consisting of a cathode and an anode, at least the cathode being a filament coil. A rare gas discharge fluorescent lamp filled with gas or krypton gas, and a series circuit consisting of a DC power source and a current limiting element connected between the anode of the rare gas discharge fluorescent lamp and one end of the cathode filament coil. , a switching element connected between the anode of the rare gas discharge fluorescent lamp and the other end of the cathode filament coil; Medium 150μs
Since it is equipped with a pulse signal source that applies a pulse signal that is open for a period of less than EC, the cathode filament is preheated during the rest period of the pulse, making the device cheaper and compared to conventional DC lighting or normal high-frequency AC lighting. This has the effect of producing a high-brightness, high-efficiency rare gas discharge fluorescent lamp without shortening its life. Further, according to another aspect of the present invention, the same effect as described above can be obtained when the filler gas is argon and the intermittent ratio is set to 5% or more and 80% or less.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of a rare gas discharge fluorescent lamp device showing an embodiment of the present invention, Fig. 2 is a lamp efficiency characteristic diagram depending on the xenon gas filling pressure in the device, and Fig. 3 is a startup diagram based on the xenon gas filling pressure. Voltage characteristic diagram, Figure 4 is a lamp efficiency characteristic diagram according to pulse energization time of a xenon gas filled lamp, Figure 5 is a lamp efficiency characteristic diagram according to pulse intermittent ratio of a xenon gas filled lamp, and Figure 6 is a pulse diagram of a xenon gas filled lamp. Life characteristic diagram by intermittent ratio, Figure 7 is cl.
) Figure 8 shows the lamp efficiency characteristic diagram depending on the krypton gas filling pressure, and Figure 8 shows the starting voltage characteristic diagram depending on the krypton gas filling pressure.
Figure 9 is a lamp efficiency characteristic diagram of a krypton gas filled lamp depending on the pulse energization time, Figure 10 is a lamp efficiency characteristic diagram of a krypton gas filled lamp depending on the pulse intermittent ratio, and Figure 11 is
The figure shows a life characteristic diagram of a krypton gas filled lamp depending on the pulse intermittent ratio, Figure 12 shows a lamp efficiency characteristic diagram depending on the argon gas filling pressure, Figure 13 shows a starting voltage characteristic diagram depending on the argon gas filling pressure, and Fig. 141! f is a lamp efficiency characteristic diagram of an argon gas-filled lamp according to the pulse energization time, Fig. 15 is a lamp efficiency characteristic diagram of an argon gas-filled lamp according to the pulse intermittency ratio, and Fig. 16 is a life characteristic diagram of the argon gas-filled lamp according to the pulse intermittency ratio. , FIG. 17 is an overall configuration diagram of a conventional rare gas discharge fluorescent lamp device, and FIG. 18 is a longitudinal sectional view of the lamp. In the figure, (3a) and (3b) are electrodes. (10) is a rare gas discharge fluorescent lamp, (11) is a glass bulb, (1
2) is a DC power supply. (13) is a current limiting element, (14)
is a series circuit, (15) is a switching element, and (16) is a pulse signal source.

Claims (2)

[Claims] (1) A rare gas discharge made by sealing xenon gas or krypton gas inside a glass bulb that has a phosphor layer formed on its inner surface and a pair of electrodes at both ends, each consisting of a cathode and anode, at least the cathode being a filament coil. fluorescent lamp,
A series circuit comprising a DC power supply and a current limiting element connected between the anode of the rare gas discharge fluorescent lamp and one end of the cathode filament coil; The switching element connected between the other end and the switching element, and the ratio of this switching element to one cycle is 5% or more and 70%.
Hereinafter, a rare gas discharge fluorescent lamp device is characterized in that it is equipped with a pulse signal source that applies a pulse signal that is open for a period of 150 μsec or less in one cycle. (2) A rare gas discharge fluorescent lamp comprising a glass bulb having a phosphor layer formed on its inner surface and a pair of electrodes at both ends, each consisting of a cathode and anode, at least the cathode being a filament coil, with argon gas sealed inside; A series circuit comprising a DC power supply and a current limiting element connected between the anode of the rare gas discharge fluorescent lamp and one end of the cathode filament coil; The switching element connected between the other end, and the switching element at a rate of 5% or more and 80% or less per cycle, once per cycle.
A rare gas discharge fluorescent lamp device comprising a pulse signal source that applies a pulse signal that is open for a period of 50 μsec or less.