JPH10275590A - Fluorescent lamp for display light - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to light a fluorescent lamp for display light with a power source voltage at 10-15 V used in a general automobile, OA equipment, and public welfare equipment. SOLUTION: Distance between electrodes in a lamp 1 is set at 0.3-3 mm, gas pressure of the sealed gas is set at 5-50 Torr, diameter of a filament is set at 0.01-0.03 mm, applying voltage to the filament 2 is set at 3-8 V, filament temperature is set at 700-1200 deg.C, and discharge stabilizing resistance 7 is set at 10-1000 Ω so as to enable to light a fluorescent lamp for display light at 10-15 V in comparison with a conventional one, in which lighting voltage at 20 V or more is required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indicator lamp for use in displaying an image on, for example, a display panel of an automobile, and more particularly to an indicator lamp capable of emitting white light by emitting a fluorescent material. The present invention relates to a fluorescent lamp for an indicator light.

[0002]

2. Description of the Related Art Conventionally, incandescent lamps have been used as this type of indicator lamp. However, as the indicator lamp has gradually become white, the color temperature of the incandescent lamp is too low, and the incandescent lamp has a blue color. When the color temperature is increased by using such a filter or the like, the loss of light quantity is remarkable, and it is difficult to cope with the loss.

[0003] Therefore, a conventional fluorescent lamp 90 for an indicator light, which is formed so as to be suitable for an indicator light as shown in FIG. Here, the configuration of the fluorescent lamp 90 for indicator lamps will be described.
The indicator lamp fluorescent lamp 90 is provided with a filament 91 to which an excitation voltage E1 such as 5 V DC is applied, and the filament 91 is coated with an electron-emitting substance 92.

An electrode 93 is provided at an appropriate distance from the filament 91, and a discharge voltage E2 is applied between the electrode 93 and the filament 91 via a discharge stabilizing resistor 96. . The filament 91 and the electrode 93 are sealed by a bulb 95 having an inner surface coated with a phosphor 94. In the sealing, an inert gas, mercury, or the like is sealed inside the valve 95.

With this configuration, in the fluorescent lamp 90 for an indicator lamp, a discharge is generated between the filament 91 and the electrode 93 by the discharge voltage E2, and the discharge excites mercury to generate ultraviolet rays. . Then, the ultraviolet light excites the phosphor 94, and as a result, the fluorescent lamp 90 for display light emits a desired white light.

[0006]

However, in the above-mentioned conventional fluorescent lamp 90 for an indicator lamp, a discharge voltage E2 of about 20 to 30 V DC is required, and only a part of automobiles such as large buses and large trucks are used. It cannot be turned on directly with the power supply voltage of 12 V except for a general automobile, and a boosting device such as an inverter is required for use, which causes a problem that an electric circuit becomes complicated.

[0007] In addition, since the power supply voltage is about 12 V in OA equipment such as personal computers and consumer equipment such as video equipment, the conventional fluorescent lamps for indicator lamps 9 are used.
0, a DC voltage of 20 to 30 V used only for the indicator fluorescent lamp 90 is applied to the discharge voltage E2.
As a result, the electric circuit similarly becomes complicated, and solving these problems has been a challenge.

[0008]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, the distance between the electrodes in the lamp is set in a range of 0.3 to 3 mm, and the gas pressure of the sealed gas is increased. Is in the range of 5 to 50 torr, the filament wire diameter is 0.01 to 0.03 mm, and the voltage applied to the filament is 3
An indicator lamp characterized in that the filament temperature is in the range of 700 to 1200 ° C. and the discharge stabilization resistance is in the range of 10 to 1000 Ω at a voltage of 10 to 15 V, and the discharge voltage is in the range of 10 to 15 V. An object of the present invention is to solve the problem by providing a fluorescent lamp.

[0009]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. 1 is a fluorescent lamp for an indicator lamp (hereinafter abbreviated as a fluorescent lamp 1) according to the present invention. The fluorescent lamp 1 is provided with a filament 2 to which an excitation voltage E1 is applied. The filament 2 has an electron-emitting substance 3 applied thereto.

An electrode 4 is provided at an appropriate distance from the filament 2. A discharge voltage E2 is applied between the electrode 4 and the filament 2 via a discharge stabilizing resistor 7. The filament 2 and the electrode 4 are sealed by a bulb 6 coated with a phosphor 5 on the inner surface, and an inert gas, mercury, or the like is sealed inside the bulb 6 at the time of sealing. It is the same as that of the conventional example.

The lighting principle of the fluorescent lamp 1 is that heat is generated by energizing the filament 2 to cause the electron emitting substance 3 to emit thermoelectrons, and the electrode 4 has a higher voltage than the voltage applied to the filament 2. A discharge voltage E2 is applied to provide a potential difference between the filament 2 and the thermoelectrons, which are cumulatively ionized by the inert gas in the bulb 6, and attract the increased electrons to the electrode 4.

In the process, the gas (mainly mercury) in the bulb 6 is excited to generate ultraviolet rays, and the ultraviolet rays excite the phosphor 5 to generate desired white light or other visible light. Although the point is the same as that of the conventional example, the present invention makes it possible to drastically lower the lighting voltage by optimizing the following items, thereby achieving the object.

Next, the optimum conditions for each item obtained in the present invention will be described. First, in the present invention, as a first condition, a distance between electrodes in a lamp is defined as a range of 0.3 to 3 mm. If the distance is 3 mm or more, with a gas pressure in the range specified as the second condition below, there is a high possibility that the distance is too long and the energy transfer of electrons ends before reaching the electrode 4. This is because a high brightness cannot be obtained.

In addition, the distance between the electrodes is not limited in principle to a shorter one.
Implementation is possible even if: However, the fluorescent lamp 1 has unavoidable problems such as deformation (sag) of the filament 2 during use or contact due to a change in mechanical dimensions of each part due to heat generation. Specifies 0.3 mm or more.

As a second condition, the present invention specifies the gas pressure of the gas sealed in the valve 6 to be in the range of 5 to 50 torr, and if the gas pressure is 5 torr or less, the mean free path of the sealed gas is defined. Since the (mean free path) becomes large, the energy is not transmitted and the light is turned off. In addition, when the gas pressure is low, the electron-emitting substance 3 evaporates remarkably, and the specified life of the fluorescent lamp 1 cannot be guaranteed.

On the other hand, if the gas pressure is 50 torr or more, the mean free path of the filling gas is small, so that the electron energy collides with the filling gas before reaching the peak value, and the amount of energy is sufficiently transmitted. Therefore, although the lighting is performed, the required brightness cannot be obtained.

Third, as a condition, the present invention specifies the temperature of the filament 2 in the range of 700 to 1200 ° C. In order to turn on the fluorescent lamp 1 at 10 to 15 V, the temperature range of the filament 2 is limited. It was confirmed from the results of trial production and examination by the inventor that this was the optimum value. Then, in order to keep the filament 2 in the above temperature range,
When the excitation voltage E1 is 3 to 8 V, the filament 2
Is obtained by setting the wire diameter to 0.01 to 0.03 mm.

As a fourth condition, the present invention specifies the resistance value of the discharge stabilizing resistor 7 to be 10 to 1000 Ω. If the resistance is 10 Ω or less, an excessive current flows between the filament 2 and the electrode 4, The discharge starting point temperature rises excessively, leading to breakage of the filament 2. On the other hand, if the resistance is 1000Ω or more, the discharge current decreases, and the brightness required for the fluorescent lamp 1 cannot be obtained.

Incidentally, according to the results of trial production and examination by the inventor for setting the above conditions, the inert gas to be enclosed is A
Any of r, Ne, Kr, and Xe may be used, or a mixture of a plurality of them may be used. Further, at this time, 0.1 to 1.0 mg of mercury is added, and ultraviolet rays are radiated with the discharge to excite the phosphor 5.

[0020]

As described above, according to the present invention, the distance between the electrodes in the lamp is in the range of 0.3 to 3 mm, the gas pressure of the filling gas is in the range of 5 to 50 torr, and the filament wire diameter is in the range of 0.1 to 3 mm. 01 to 0.03 mm, the applied voltage to the filament is 3 to 8 V, and the filament temperature is 700 to 1200.
° C and the discharge stabilizing resistance is in the range of 10 to 1000Ω, which is one to less than this type of fluorescent lamp for an indicator lamp, which conventionally required a lighting voltage of about 20 V or more.
This enables lighting in the range of 0 to 15 V. This makes it possible to increase the voltage of the booster circuit for devices that use a power supply voltage in the above range, such as general automobiles, most OA devices, and most consumer devices. This makes it possible to use the apparatus without complicating the structure of the apparatus, such as the use thereof, and has an extremely excellent effect in reducing the cost of equipment employing this type of fluorescent lamp for an indicator lamp. Also, since the fluorescent lamp for the indicator lamp can be directly turned on by the power supply of the above-described device, the use can be expanded.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a fluorescent lamp for an indicator lamp according to the present invention.

FIG. 2 is a sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fluorescent lamp for indicator lights 2 ... Filament 3 ... Emissive substance 4 ... Electrode 5 ... Phosphor 6 ... Valve 7 ... Discharge stabilization resistance E1 ... Excitation voltage E2 ... Discharge voltage

Claims (2)

[Claims] 1. The distance between electrodes in a lamp is in the range of 0.3 to 3 mm, the gas pressure of the filling gas is in the range of 5 to 50 torr, the filament wire diameter is 0.01 to 0.03 mm, and application to the filament is performed. The voltage is 3 to 8 V, the filament temperature is in the range of 700 to 1200 ° C., and the discharge stabilizing resistance is 1
By setting the range of 0 to 1000Ω, the discharge voltage becomes 10
A fluorescent lamp for an indicator lamp, which can be turned on in a range of up to 15 V. 2. The method according to claim 1, wherein the sealing gas is Ar, Ne, Kr, or X.
e alone or as a mixture, and 0.1 to 1.0 mg
2. The fluorescent lamp for an indicator light according to claim 1, wherein mercury is added.