JPH0757882A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To extend the life of a discharge lamp by suppressing the deterioration of both electrodes of the discharge lamp. CONSTITUTION:A fluorescent lamp 1 formed of a discharge tube 1c having a phosphor applied thereto, and a pair of electrodes 1a, 1b provided on both ends of the discharge tube 1c is lighted. A discharge lamp lighting device has a ballast 4 connected between a power source 10 and the fluorescent lamp 1, and a glow starter 5 having a fixed pole and a movable pole and connected to both the electrodes 1a, 1b through the switch part 2SW of a ratchet relay 2. The ratchet relay 2 alternately switches the poles of the glow starter 5 connected to both the electrodes 1a, 1b every lighting of the fluorescent lamp 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device for lighting a discharge lamp such as a fluorescent lamp for illuminating a product for sale displayed in a showcase.

[0002]

2. Description of the Related Art Conventionally, in a showcase, as shown in, for example, Japanese Patent Application No. 4-78437 filed by the applicant earlier, a fluorescent lamp (a discharge lamp) for illuminating the inside of the cabinet on the back side of each shelf. ) Is provided. Then, a glow starter is attached to each fluorescent lamp, and at the same time when the power is turned on, the fluorescent lamp is started and turned on by the glow starter.

That is, an electric circuit of a conventional discharge lamp lighting device 50 for lighting the fluorescent lamp shown in FIG. 4 is shown. The discharge lamp lighting device 50 includes a glow starter 5 connected to a fluorescent lamp 1 as a discharge lamp, a commercial AC power source 10, and a fluorescent lamp 1.
It is composed of a ballast 4 composed of a choke coil and a power switch 3 which are connected between them. The fluorescent lamp 1 comprises a discharge tube 1c made of a cylindrical elongated glass tube whose inner wall surface is coated with a phosphor, and a pair of electrodes (filaments) 1a and 1b provided at both ends of the discharge tube 1c.
Ultraviolet radiation generated by discharge in low-pressure mercury vapor is discharged from the discharge tube 1c.
It is to convert to visible light with the phosphor.

On the other hand, the glow starter 5 is generally shown in FIG.
As described above, the fixed pole 15a, the movable pole 15b provided with a predetermined distance from the fixed pole 15a and provided with the bimetal 15c at the tip, and the fixed pole 15a and the movable pole 15b.
And a pair of terminals 5a and 5b which are connected to the fixed pole 15a and the movable pole 15b and are pulled out from the glass tube 15d.
It consists of and. The fixed electrode 15a and the movable electrode 15b have a thin pin shape, and the bimetal 1 of the movable electrode 15b is formed.
5c has a wide plate shape. And the glass tube 15
Ne (neon) or Ar that assists the discharge in d
(Argon) gas is sealed and the lower opening is sealed with an insulating resin.

Both terminals 5a and 5b are attached to a socket (not shown), for example, the terminal 5a (fixed electrode 15a).
The side) is on one electrode 1a of the fluorescent lamp 1 and the terminal 5b.
The (movable pole 15b side) is connected to the other electrode 1b of the fluorescent lamp 1. Here, this type of fluorescent lamp 1 has a property that the voltage of the electrodes 1a and 1b decreases as the current flowing therein increases. Therefore, it is necessary to insert a current limiting element for operating the fluorescent lamp 1 in a stable manner in series with the fluorescent lamp 1. Therefore, the ballast 4 functions as a current limiting element for the commercial AC power supply 1
0 and the electrode 1b of the fluorescent lamp 1 are connected. The power switch 3 is connected between the electrode 1 a of the fluorescent lamp 1 and the commercial AC power supply 10.

When the power switch 3 is closed in the above configuration, the voltage of the commercial AC power source 10 is converted into a high voltage by the ballast 4 and applied to the glow starter 5. Glow starter 5
When a high voltage is applied to the gas, the enclosed Ne (neon) or Ar (argon) gas discharges between the fixed electrode 15a and the bimetal 15c of the movable electrode 15b to generate heat. The movable electrode 15b is heated by the heat generated during the discharge, and the bimetal 15c contacts the fixed electrode 15a.
When the bimetal 15c and the fixed pole 15a come into contact with each other,
Since a current flows through the electrodes 1a, 1b of the discharge tube 1c to heat it, the temperature becomes a temperature at which thermoelectrons are easily emitted.

On the other hand, when the bimetal 15c and the fixed electrode 15a come into contact with each other, the discharge is stopped, and after 1 to 2 seconds, the bimetal 15c cools and separates from the fixed electrode 15a. At this time, a high-voltage pulsed surge voltage is generated in the ballast 4, and this voltage is applied between both electrodes 1a and 1b of the discharge tube 1c at a temperature at which thermoelectrons are easily emitted to start discharge,
That is, the fluorescent lamp 1 is started.

[0008]

The surge voltage applied to the glow starter 5 is the movable electrode 1 having a large surface area.
Since it is absorbed by the bimetal 15c on the 5b side,
Discharge does not easily occur from the electrode 1b of the fluorescent lamp 1 connected to the movable pole 15b, and in most cases, the fixed pole 1 having a small area.
Discharge starts from the electrode 1a connected to 5a. Therefore, the fluorescent lamp 1 is always discharged from the side of the electrode 1a connected to the fixed electrode 15a every time the power switch 3 is turned on.

When the electrode 1a is discharged, mercury ions generated during the discharge collide with the electrode 1a and are scattered, so that the electrode 1a is significantly deteriorated due to blackening. On the other hand, the terminals 5a and 5b of the glow starter 5 and the electrodes 1a and 1 of the fluorescent lamp 1 are
Since the relationship of b does not change until the glow starter 5 is replaced, there is a problem that the life of the fluorescent lamp 1 is significantly shortened due to the deterioration of the one electrode 1a.

The present invention has been made in order to solve the above-mentioned conventional technical problems. By suppressing the deterioration of both electrodes of the discharge lamp, it is possible to extend the life of the discharge lamp. An object is to provide a discharge lamp lighting device.

[0011]

That is, the discharge lamp lighting device according to the invention of claim 1 is a discharge lamp comprising a discharge tube coated with a phosphor and a pair of electrodes provided at both ends of the discharge tube. And a ballast connected between a power source and a discharge lamp, and a glow starter having a fixed pole and a movable pole and connected to both electrodes via a switching means. Therefore, the switching means alternately switches the poles of the glow starter connected to both electrodes every time the discharge lamp is turned on.

A discharge lamp lighting device according to a second aspect of the present invention is for lighting a discharge lamp comprising a discharge tube coated with a phosphor and a pair of electrodes provided at both ends of the discharge tube. And an oscillator connected to the power supply and a switching means connected between the output terminal of the oscillator and both electrodes, the switching means being connected to both electrodes each time the discharge lamp is turned on. The output terminals of the oscillator are switched alternately.

[0013]

According to the discharge lamp lighting device of the first aspect of the present invention, the switching means connected between both electrodes of the discharge lamp and the fixed pole and the movable pole of the glow starter turns on each time the discharge lamp is lit. Since the poles of the glow starter connected to the electrodes are switched alternately, the electrodes for discharging are switched alternately each time the discharge lamp is turned on. Therefore, deterioration of only one of the electrodes can be prevented, and as a result, the life of the discharge lamp can be extended.

Further, according to the discharge lamp lighting device of the second aspect, when the discharge lamp is lighted by the oscillator, the switching means alternately switches the electrodes of the discharge lamp connected to the output terminal of the oscillator every lighting. Also in this case, the electrodes for discharging are alternately switched every time the discharge lamp is turned on. Therefore, similarly, deterioration of only one of the electrodes is prevented, and as a result, the life of the discharge lamp can be extended.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is an electric circuit diagram of a discharge lamp lighting device 20 of the present invention,
2 is an electric circuit diagram of another discharge lamp lighting device 30 of the present invention, and FIG. 3 is a perspective view of the glow starter 5. 1 to 3, the same reference numerals as those in FIG. 4 are the same.

In FIG. 1, a discharge lamp lighting device 20 is a device for lighting a fluorescent lamp 1 as a discharge lamp provided in a storehouse of a showcase (not shown), for example, and includes a glow starter 5 and a choke coil. And a ratchet relay 2 as switching means.
Both electrodes 1a and 1b of the fluorescent lamp 1 similar to the above are connected to the glow starter 5 via the switch portion 2SW of the ratchet relay 2 as a switching means, and the electrode 1 of the fluorescent lamp 1 is connected.
The ballast 4 is connected in series to b, and the commercial AC power supply 10 is connected to the input side of the ballast 4. Furthermore, fluorescent light 1
The electrode 1a of is connected to the commercial AC power source 10 via the power switch 3. Further, the ratchet relay 2 (coil) is connected between the subsequent stage of the power switch 3 and the input side of the ballast 4.

Switch portion 2SW of ratchet relay 2
Is two common terminals 2e, 2f and each common terminal 2
Switching terminals 2a, 2 provided for e and 2f, respectively
The fluorescent lamp 1 is connected to the terminal 2e, and the electrode 1b is connected to the terminal 2f. The terminals 2a and 2d are connected to the terminal 5b connected to the movable pole 15b of the glow starter 5, and the terminals 2b and 2c are connected to the terminal 5a connected to the fixed pole 15a of the glow starter 5.

The ratchet relay 2 is configured to switch the switch section 2SW every time the power switch 3 is closed. That is, for example, assuming that the switch unit 2SW of the ratchet relay 2 is currently closed to the terminals 2e-2a and 2f-2c, when the power switch 3 is closed and the ratchet relay 2 is energized, the switch unit 2SW will switch to the terminal 2e.
-2a, 2f-2c to terminals 2e-2b, 2f-2d. Then, when the power switch 3 is closed next time,
This time, it switches to the closed state of 2e-2a, 2f-2c, and thereafter, every time the power switch 3 is closed, the switch unit 2S is closed.
The state of W is switched.

Next, the discharge lamp lighting device 2 of FIG.
The operation of 0 will be described. Now, it is assumed that the switch portion 2SW of the ratchet relay 2 is closed to the terminals 2e-2a and 2f-2c, and when the power switch 3 is closed in FIG. 1, the commercial AC power source 10 is connected and a voltage is applied to the discharge lamp lighting device 20. Supplied. At this time, the ratchet relay 2 is driven and the switch unit 2SW operates to operate the terminals 2e-2b, 2f-.
It switches to the closed state in 2d. The supplied voltage is converted into a high voltage by the ballast 4, and is applied to the glow starter 5 via the terminals 2e-2b and 2f-2d of the switch unit 2SW. When a high voltage is applied to the glow starter 5, the Ne (neon) or Ar (argon) gas sealed in the glow starter 5 discharges and generates heat.

When the bimetal 15c of the glow starter 5 is heated by the above-mentioned discharge and comes into contact with the fixed electrode 15a, the discharge is stopped, and the discharge tube 1c passes through the terminals 2e-2b and 2f-2c of the switch section 2SW. Electrode 1
Electric current flows through a and 1b to generate heat, and the temperature becomes a temperature at which thermoelectrons are easily emitted. And, after 1-2 seconds, bametal 15c
Is cooled and separated from the fixed pole 15a, so that a surge voltage is generated in the ballast 4. This surge voltage is the switch part 2SW
Fixed electrode 1 of glow starter 5 via terminals 2e-2b of
5a (terminal 5a) is applied to the electrode 1a of the fluorescent lamp 1 that is currently connected, and discharge is generated from there to turn on the fluorescent lamp 1.

Next, when the power switch 3 is opened to turn off the fluorescent lamp 1 and then the power switch 3 is closed again, the ratchet relay 2 is driven to operate the switch section 2SW, and its terminals 2e-2b, 2f-2d. The one that was closed is terminal 2e
-2a, 2f-2c is switched to the closed state. As a result, the surge voltage generated in the ballast 4 is applied to the electrode 1b of the fluorescent lamp 1 connected to the fixed pole 15a (terminal 5a) of the glow starter 5 through the terminals 2f-2c of the switch unit 2SW. From there, discharge occurs and the fluorescent lamp 1 is turned on.

That is, each time the power switch 3 is closed and the fluorescent lamp 1 is turned on, the discharging electrodes 1a and 1b are alternately switched, so that deterioration due to blackening of only one electrode is suppressed and both electrodes 1a and 1a are suppressed. 1b deteriorates substantially uniformly. As a result, the life of the fluorescent lamp 1 is extended. Next, FIG. 2 shows an electric circuit diagram of a discharge lamp lighting device 30 for lighting the fluorescent lamp 1 by an oscillator such as an inverter. In the figure, the same symbols as those in FIG. 1 are the same. In this case, the discharge lamp lighting device 30 includes the electrode 1 of the fluorescent lamp 1.
It is composed of a resonance capacitor 8 connected in series with a and 1b, an inverter oscillator 6, a ratchet relay 2, and a resonance coil 7. The input of the oscillator 6 is connected to the commercial AC power source 10 via the power switch 3, and the switch terminal 2SW of the ratchet relay 2 is connected to the output terminal 6a thereof.
Is connected to the common terminal 2e, and the output terminal 6b is connected to the common terminal 2f via the resonance coil 7.

The terminals 2a and 2d of the ratchet relay 2 are connected to the electrode 1b of the fluorescent lamp 1 and the terminal 2b.
And 2c are connected to the electrode 1a of the fluorescent lamp 1. still,
The ratchet relay 2 is connected to the commercial AC power source 10 as described above. On the other hand, the inverter oscillator 6 generates a rectangular pulse having a predetermined frequency from the input commercial power source and outputs the rectangular pulse from the output terminal 6a. When the fluorescent lamp 1 is turned on, the frequency of this pulse is output to the resonance capacitor 8 and the resonance coil 7. The resonance frequency is changed to the vicinity, and the electrodes 1a, 1 of the fluorescent lamp 1
The discharge is started by increasing the current flowing in b and heating it. Therefore, similarly, since the discharge is performed from the electrode connected to the output terminal 6a, the deterioration of the electrode becomes severe.

However, in the present invention, the power switch 3
Each time you close, the ratchet relay 2 operates as described above,
The switch unit 2SW alternately switches between a state in which the terminals 2e-2b and 2f-2d are closed and a state in which the terminals 2e-2a and 2f-2c are closed. Therefore, the output terminal 6 of the oscillator 6
Since the electrode connected to a is switched between 1a and 1b each time the power is turned on, deterioration due to blackening of only one electrode is suppressed as described above, and both electrodes 1a and 1b are deteriorated substantially uniformly. . As a result, the life of the fluorescent lamp 1 is extended.

In the embodiment, the straight tube fluorescent lamp 1 is taken as an example, but the present invention is not limited to this, and the present invention is also effective for a tube having an annular or spherical discharge tube.

[0026]

As described in detail above, according to the invention of claim 1, the switching means connected between both electrodes of the discharge lamp and the fixed pole and the movable pole of the glow starter each time the discharge lamp is turned on. Since the electrodes of the glow starter connected to both electrodes are switched alternately, the electrodes that perform discharge can be switched alternately each time the discharge lamp is lit, thereby preventing deterioration of only one of the electrodes. Therefore, the life of the discharge lamp can be remarkably extended.

According to the second aspect of the invention, when the discharge lamp is lit by the oscillator, the switching means alternately switches the electrodes of the discharge lamp connected to the output terminal of the oscillator every lighting. Therefore, in this case Also, it becomes possible to alternately switch the electrodes for discharging each time the discharge lamp is lit, and similarly, to prevent deterioration of only one of the electrodes,
The life of the discharge lamp can be remarkably extended.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a discharge lamp lighting device of the present invention using a glow starter.

FIG. 2 is an electric circuit diagram of a discharge lamp lighting device of the present invention using an oscillator.

FIG. 3 is a perspective view of a glow starter.

FIG. 4 is an electric circuit diagram of a conventional discharge lamp lighting device.

[Explanation of symbols]

 1 Fluorescent lamp 2 Ratchet relay 2 SW switch section 4 Ballast 5 Glow starter 6 Inverter oscillator

Claims (2)

[Claims] 1. A discharge lamp lighting device for lighting a discharge lamp comprising a discharge tube coated with a phosphor and a pair of electrodes provided at both ends of the discharge tube. A ballast connected to the electrodes, a fixed electrode and a movable electrode, and a glow starter connected to the electrodes via switching means, the switching means each time the discharge lamp is turned on. A discharge lamp lighting device, characterized in that the poles of the glow starter connected to the both electrodes are alternately switched. 2. A discharge lamp lighting device for lighting a discharge lamp comprising a discharge tube coated with a phosphor and a pair of electrodes provided at both ends of the discharge tube, and an oscillator connected to a power source. An output terminal of the oscillator and switching means connected between the electrodes, the switching means alternately connecting the output terminals of the oscillator connected to the electrodes each time the discharge lamp is turned on. A discharge lamp lighting device characterized by switching to.