JPH02135658A - Transitable light source apparatus - Google Patents

Abstract

PURPOSE:To provide an inexpensive transitable light source apparatus capable of serving as a main illumination by controlling an electric power for heating a cathode, and varying a light emitting ratio of mercury vapor and inactive gas. CONSTITUTION:An electric power for heating a cathode 2 is controlled. At the time of lighting without heating the cathode 2, an electron having energy equivalent to a cathode falling voltage is flown from the cathode 2 into a space. The energy is enough to ionize and energize inactive filled gas. And further, the filled pressure of the inactive gas is far higher than a mercury vapor pressure. Accordingly, in a lamp, light emission caused by the inactive gas tends to be stronger. Meanwhile, at the time of lighting while heating the cathode 2, the cathode falling voltage is low because a temperature at the cathode 2 is high. consequently, flying energy of the electron is reduced so that a ratio of ionizing and energizing the inactive gas is also reduced. Therefore, the light emission ratio of the mercury vapor and the inactive gas can be varied, and thus, light emitting color of the lamp can be changed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable color light source device that can change the color of light with one lamp.

Prior Art] Much research and development has been conducted on variable color light source devices, and some of them have been put into practical use.

However, most of them combine red, blue, and green color incandescent lamps or color fluorescent lamps into one unit, and then combine them into a single unit.
The idea was to emit light and change the color of the light.

[Problems to be Solved by the Invention] Although such a light source device is certainly color variable, it has the following drawbacks.

(1) It is expensive because it requires a light control device.

(2) Since three lamps are combined into one, it is large and the luminous flux is small.

Due to the above drawbacks, it was not suitable for use as main lighting.

The present invention has been made in view of the above drawbacks, and its purpose is to provide a variable color light source device that is inexpensive and can be used as main illumination.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a tube whose inside is filled with mercury vapor and an inert gas, has translucency, and whose inner surface is coated with a phosphor. A lamp consisting of a thermionic-emitting cathode disposed inside the tube and an electron-transmissive anode disposed at a distance of several millimeters to several ports from the cathode is heated at a constant current. By lighting the cathode with a constant voltage source or impedance connected in series and controlling the electric power that heats the cathode, the luminous ratio of the mercury vapor and inert gas is changed to realize variable colors. .

[Function] When the lamp having the above configuration is lit without heating the cathode, electrons fly out from the cathode into space with energy corresponding to the cathode drop voltage.

This energy is more than ten volts, which is sufficient to ionize and excite the enclosed inert gas (both ionization voltage and excitation voltage are higher than mercury). Moreover, the sealing pressure is compared to the mercury vapor pressure (about 10-' Torr).
The inert gas pressure (0.5 Torr to 10-odd Torr) is sufficiently high, so that the lamp emits light from the inert gas quite strongly.

On the other hand, if the above lamp is lit while heating the cathode,
Since the cathode temperature is high, the cathode drop voltage is low. Therefore, the energy of the electrons jumping out also decreases, and the rate at which the inert gas is ionized and excited decreases.

In this way, by controlling the cathode heating power,
The ratio of light emission between mercury vapor and inert gas can be changed, and the color of light emitted from the lamp can be changed.

[Example] Figure 1 shows an example of the lamp according to the present invention.
1 is a spherical tube with an outer diameter of 50 mm, the inner surface of which is coated with a light bulb-colored phosphor (not shown), and the inside of which is filled with mercury vapor (10-2 to 1 O-4 Torr). Approximately 5 Torr of neon gas is sealed.

A cathode 2 is disposed inside the tube body 1 and is made of a tungsten filament coated with a barium emitter. 3 is an electron-permeable anode disposed at a distance of several III+ from the cathode 2.

The lamp thus constructed was lit using a basic circuit as shown in FIG. In addition, in FIG. 2, 4 is a cathode heating power source, and 5 is a constant current source.

Here, by flowing a current of 600 mA and changing the cathode heating power source 4 from O to 7■, point A (x = 0.534.)' = 0 in the chromaticity diagram shown in Fig. 3.
．． 398 ) to point B (x = 0.439. Y =
It was possible to change the emission color in a range up to 0.435 ).

Next, FIG. 4 shows a different embodiment of the present invention, which differs from the previous embodiment in that it has a configuration intended for AC lighting. In the figure, 1 is a tube body, 2.3 is a thermionic emission type electrode, 4 is an electrode heating power source, 6 is an impedance element, and 7 is an AC power source.

In this example, as in the previous example, the color of the emitted light could be changed by controlling the heating of the electrode 2.3.

[Effects of the Invention] As described above, the present invention comprises a tube whose interior is filled with mercury vapor and an inert gas, has translucency, and whose inner surface is coated with a phosphor; A lamp consisting of a thermionic-emitting electrode and an electron-transmissive electrode placed at a distance of several mm to several centimeters from the electrode is turned on to heat at least one of the electrodes. By controlling it, it is possible to provide a variable color lamp, and it does not require a complicated dimming circuit like conventional ones, is very inexpensive, and since it is a single lamp, it is small in size, and the output can be used for main lighting. Get as much as you can.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the lamp according to the present invention;
FIG. 2 is a schematic block diagram showing one embodiment of the present invention, FIG. 3 is a chromaticity diagram according to the present invention, and FIG. 4 is a schematic block diagram showing a different embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Tube body, 2... Electrode (cathode), 3... Electrode (anode), 4... Electrode (cathode) heating means,
5... Constant current supply means, 6.7... Constant voltage supply means.

Claims (2)

[Claims] (1) A translucent tube whose inside is filled with mercury vapor and inert gas, and whose inner surface is coated with phosphor, and a thermionic-emitting cathode disposed inside the tube. a lamp comprising an electron-permeable anode disposed at a distance of several mm to several cm from the cathode; and a cathode heating means capable of constantly heating the cathode and controlling the heating power. and constant current supply means for supplying a constant current between the anode and the cathode. (2) A tube body that is filled with mercury vapor and inert gas, has translucent properties, and has a phosphor coated on its inner surface, and a tube body that has an interval of several mm to several centimeters inside the tube body. A lamp consisting of a pair of thermionic emission type electrodes arranged to face each other, an electrode heating means capable of constantly heating each of the electrodes and controlling the heating power, and a constant voltage applied between the electrodes. A variable color light source device comprising a lighting device having constant voltage supply means.