JPH01217886A - Discharge lamp lighting system - Google Patents

Abstract

PURPOSE:To prevent a short life of a discharge lamp generated when a preheating condition of a filament is not normal by providing a control circuit part which substantially controls an output of a lighting circuit part by an output of a mounted detection part. CONSTITUTION:A preheating current detection circuit B detects a preheating current at the time of preheating and lighting by current detection elements 1a, 1b, while outputting a current detection signal corresponding to the preheating current by detection output circuits 2a and 2b. Then, a comparison circuit C compares a current detection signal corresponding to the preheating current with reference voltage set up in a reference voltage generating circuit E, while generating a normal signal, when the preheating current flowing through the respective filaments f1 and f2 is judged as normal, and an abnormal signal, when being judged as abnormal. In a control circuit D in the next stage, when the normal signal is received, a relay Ry is made in a nonoperation state, and in case of an abnormal signal, the relay is made in an operation state. By the operation of this relay Ry, the contacts S1 and S2 are put in the state OFF so as to put out a discharge lamp.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a discharge lamp lighting device that supplies power to a discharge lamp having a filament.

(Prior art) Conventionally, this type of discharge lamp was lit! A widely used type of A-type discharge lamp lighting device is a so-called rabbit start type discharge lamp lighting device that boosts the voltage of an AC power source and further limits the current to stably supply power to the discharge lamp.

Furthermore, recently, there have been an increase in the number of devices that use means for converting to high frequencies.

This conventional example will be explained below.

FIG. 7 shows a conventional example of a device using such a means for converting into high frequency, and its configuration is based on AC power supply A ("
A high-frequency inverter circuit A as a lighting circuit unit receives power supply from the high-frequency inverter circuit A and outputs a high-frequency output voltage V2, and a discharge having a pair of filaments fl and f2 coupled to the high-frequency output voltage V2 of the high-frequency inverter circuit A. It consists of a light.

Here, points A, C, C and 2 indicate connection points when the filaments fl and f2 of the discharge lamp are inserted into the socket (not shown).

In a discharge lamp lighting device that uses such a high-frequency inverter circuit A to start and light the filaments fl and f2 after preheating, the voltage V2 applied to both ends of the discharge lamp is generally used to start the discharge lamp. Because the voltage is sufficient, for example, a pair of filament terminals installed at both ends of a discharge lamp) 1. A state in which only one of the respective terminals of f2 is disconnected (as shown in Figure 7) Even if one of the points is far away, the discharge lamp may start and turn on once.

This is because the discharge starting voltage of a discharge lamp is not constant and changes depending on the scattering of the cathode oxide attached to the filament and the deterioration of the gas filled in the discharge lamp. This is because the value is set high considering the lifespan of the discharge lamp.

Therefore, if the discharge lamp has not yet reached the end of its service life, it is quite possible that the lamp will light up even in a one-sided preheating state in which the preheating current flows through only one filament.

Now, if such a discharge lamp with one side preheated is used repeatedly for starting and lighting, the filament will wear out quickly, leading to early startup failures, or short-term disconnection, which will lead to malfunctions. This caused problems with the short lifespan of discharge lamps, including the early blackening of the tube wall due to the scattering of constituent materials of the filament, leading to a decrease in luminous flux.

This is because electrons are extracted with high energy from the filament, which is the cathode, in a high electric field, and the electrons collide with the filament on the anode side, raising the temperature of the anode filament. The number of collisions with electrons and other atoms is small due to the small number of electrons, and the loss of energy due to the loss of electrons is small. Also, mercury atoms, etc. that exist near the anode do not receive the collisions of these electrons by themselves. It is explained that the cause is that electrons are emitted, become ion atoms, collide with the cathode, and pull out atoms from the cathode constituent material (sputtering).

In addition, other conventional examples include an interlock that cuts off the input current to the discharge lamp lighting device when there is no load and no discharge lamp is installed, since the voltage sufficient for starting is high and dangerous. A configuration using a mechanism is known. This interlock mechanism is especially provided in sockets that use straight tube fluorescent lamps, and allows a spring-type switch to be turned on by the pressure of attaching the lamp, and turned off by removing the lamp. is used to turn the input terminal on and off.

Therefore, although the original function of detecting the lamp installation state is sufficient, it is not possible to detect whether or not current is flowing through each filament, resulting in the same problem as described above.

Furthermore, as a means for detecting an abnormal state during lighting of a discharge lamp, an example of detecting abnormal voltage during half-wave discharge described in Japanese Patent Publication No. 62-10000 is also known; There is nothing disclosed about detecting whether or not a discharge lamp is reliably installed in a socket while a preheating current is flowing through the filament of the electric lamp, and as in the previous explanation, the problem of the short lifespan of discharge lamps remains unresolved.

(Problems to be Solved by the Invention) As described above, in the conventional discharge lamp lighting device, the life of the discharge lamp is shortened due to repeated starting and lighting even when a normal preheating current does not flow through the filament. There was a problem.

The present invention has been made to improve the above-mentioned problems, and its purpose is to prevent the short life of the discharge lamp that occurs when the preheating state of the filament of the discharge lamp is not normal. .

[Structure of the invention]

(Means for solving the problem) The present invention provides a discharge lamp having a filament that is lit by power supply from a lighting circuit section, a preheating circuit section that supplies preheating current to each of the filaments, and a discharge lamp that supplies preheating current to each of the filaments. The present invention is characterized by comprising an attachment detection section that detects an abnormal connection state with the filament, and a control circuit section that substantially limits the output of the lighting circuit section based on the output of the attachment detection section.

(Function) As described above, the present invention detects the attachment state between the preheating circuit section of the discharge lamp lighting device and the filament of the discharge lamp using the attachment detection section, and prevents the preheating current from flowing normally to each filament. In the case of an abnormal connection state that causes such a situation, by substantially limiting the output of the discharge lamp lighting device, such as reducing or stopping the output or blinking, it is possible to reduce the short life of the discharge lamp that would otherwise occur if the lamp is used as is. You can protect yourself from 1 hit before it happens.

<Example) Hereinafter, the present invention will be explained in detail based on examples.

FIG. 1 shows the basic configuration of the present invention, in which power is supplied from this lighting circuit section Δ to a lighting circuit section such as a high frequency inverter circuit coupled to an AC power source AC. a pair of filaments that light up in response to a discharge lamp such as a fluorescent lamp having fl and f2, and the pair of filamen)
Preheating circuit section Δf that supplies preheating current to N and f2, respectively
1. Af2, this preheating circuit section Afl, Af2 and 11η
(FILAMENT) A mounting detection section X that detects an abnormal connection state with fl and f2, and a control circuit section that turns off the output of fl and Af2 to one of the preheating circuit sections based on the output of this mounting detection section X. It consists of

The attachment detection section It is composed of a comparison circuit C that compares the output with that of the detection circuit B.

The preheating current detection circuit B includes current detection elements 1a and 1 that detect the preheating current flowing from each preheating circuit section to the filament.
b, and detection output circuits 2a and 2b which receive human power from the current detection elements 1a and 1b and output current detection signals.

The control circuit section includes a control circuit 4 which receives the output of the comparator circuit C and outputs a control signal, and a control circuit 4 which receives the output of the comparison circuit C and outputs a control signal, and a contact Sl which receives this output.
, and a relay Ry which is an opening/closing means for opening/closing operations of S2.

The basic circuit operation will be explained below using the basic block configuration of the present invention shown in FIG.

First, when the power switch SW is turned on, the alternating current power supply AC is applied to the high frequency inverter circuit A, and the high frequency output voltage v
2 is generated at the output end of the high frequency inverter circuit A. A pair of filaments 11 located at both ends of the discharge lamp
．． A preheating current is supplied to the discharge lamp 1. It lights up when applied to both ends of.

At this time, the P thermal current detection circuit B inserted between the preheating circuit parts Aft, Af2 and the respective filaments fl, f2 is the current detection element 1a.

lb detects the preheating current during preheating and during lighting, and the detection output circuits 2a and 2b output a current detection signal corresponding to the preheating current. Then, the comparison circuit C compares the current detection signal corresponding to the preheating current with the reference voltage set by the reference voltage generation circuit E, and compares each filament fl, f2.
If the preheating current flowing in the preheating current is determined to be normal, a normal signal is generated, and if it is determined to be abnormal, an abnormal signal is generated.

In the next stage control circuit section, when a normal signal is received, a control signal is output from the control circuit 4 to put the relay Ry into an inoperable state, and when an abnormal signal is received, a control signal is output from the control circuit 4. The signal is output and the relay Ry is put into operation.

Due to the operation of this relay Ry, contacts S1. S2 is turned off and the discharge lamp is turned off.

Therefore, the filament f1 of the discharge lamp. When normal preheating current does not flow to f2 (for example, one side is preheated)
Therefore, it is possible to reliably cut off the discharge lamp from the lighting circuit section.

Next, FIG. 2 shows a first embodiment of the present invention, in which the basic block configuration shown in FIG. 1 is made into a concrete circuit configuration.

Note that parts having the same functions as the basic block configuration shown in FIG. 1 are given the same reference numerals and redundant explanations will be omitted.

The lighting circuit section Δ converts the AC power supply AC into a DC voltage using a high frequency oscillation circuit, converts this into a high frequency voltage, and generates a high frequency output voltage between the secondary windings of the step-up transformer OT.

A discharge lamp has a pair of filaments at both ends.

2 of the step-up transformer OT.
Connected between the next windings, a pair of timer members) fl, f2
A preheating current is supplied from a winding provided in the step-up transformer OT.

The current detection elements 1a and lb are current transformers CTI
, Cr2 is used.

The detection output circuits 2a and 2b are rectifier diodes D1 and D2.
, smoothing capacitors C1 and C2, and outputs a DC voltage according to the preheating current as a current detection signal.

The comparison circuit C includes comparison circuits 3a and 3b corresponding to the detection output circuits 2a and 2b, and has an OR output at each output terminal.
A circuit OR is provided to output a normal or abnormal signal.

Here, the comparison circuit 3a is composed of comparators CI and C2 such as comparator IC, and a first reference voltage VcO of approximately zero voltage is applied to the + side terminal of the comparator C1, and the first reference voltage VcO of approximately zero voltage is applied to the one side terminal of the comparator C2. Add a second reference voltage Vcl of a predetermined voltage to ) between the current detection signal V of the preheating current detection circuit B
in is input. Here, the current detection signal Vi
n varies from the first reference voltage VcO to the second reference voltage Vcl
It is set so that a normal signal is output when the value is between 1 and 2, and an abnormal signal is output in other cases. Also, comparator C
3. Since C4 is similarly configured, the explanation will be omitted.

The reference voltage generation circuit E is a step-up transformer O to the lighting circuit section.
A winding TI is provided at T to receive power supply, and the rectifier DB1
, a smoothing capacitor C3, a resistor R1, and a constant voltage diode ZDI, and have first and second reference voltages VcO,
Vcl is output to the comparators C1, C2, C3, and C4. Note that although the first reference voltage VcO is shown here by the symbol of circuit ground in the figure, this is the same as the current detection signal Vin.
This is to detect the zero voltage of the second reference voltage Vcl
It goes without saying that a predetermined value may be set in the same manner as in .

The control circuit section includes a timer circuit T that generates a timer signal after a predetermined time has elapsed from the start of operation of the first reference voltage generation circuit E, and an AND circuit in which the output of the comparison circuit C and the output of the timer circuit T are input manually. AND and a resistor R2 at this output terminal.
and a relay Ry connected in series with the transistor Tr across the constant voltage diode ZDI of the reference voltage generating circuit E. When receiving the timer signal, it drives relay Ry and contacts S1.3
2 is turned off.

Here, the contacts St and S2 are the preheating circuit section Afl.

It is inserted into both of the two light tube wires a and b of Ar1.

The embodiment shown in FIG. 2 will be described below with reference to FIGS. 4 to 6.

Now, when the power switch SWI is turned on, the lighting circuit section receives power from the alternating current power supply AC, starts operating, generates a high frequency output voltage at the output terminal, and lights the discharge lamp.

Here, since the polarities of the step-up transformers O'F are set in the same direction, the potential between the connection point opening and the connection point 2 is the highest. Therefore, the lamp current 11a flows through the tube light lines a and d, which have the largest potential difference. Therefore, the preheating current If of the filaments fL and f2 as shown in FIG. 4 flows through the tube light wires a, c, and
d, a combined current of the preheating current If and the lamp current 11a as shown in FIG. 5 flows.

In this embodiment, since the current transformers CTI and CT2 are inserted into the tube light lines c, it is possible to detect the preheating current shown in FIG. 4 during normal operation as described above. The current detection signal Vin when the lamp is in a good connection state becomes the current detection signal Vfl during normal operation as shown in FIG. 6(a).

Next, the installation condition of tube light line a (or tube light line d) is poor and there is a poor connection (for example, when the connection point or connection point 2 is far apart)
The current detection signal Vin at the time becomes the current detection signal Vf2 at the time of abnormality as shown in FIG. 6(b). This is the lamp current 11a in the current transformer CTl or (Cr2).
This is because it flows. - Generally, the lamp current 11a is set larger than the preheating current If, and the current detection signal V
in has a relationship of Vfl<VF6.

Furthermore, the current detection signal ■in when the tube light line b (or tube light line C) is not installed well and has poor contact (for example, when connection point A or connection point C is far apart) is as follows: Figure 6 (C)
The abnormal current detection signal Vf3 is approximately zero voltage as shown in FIG. This is the current transformer CTI or (CT2
This is because no current flows through ).

Therefore, the preheating current detection circuit B detects the filament 1-f.
1. It is possible to detect the connection status of all connection points of f2, and
It can be detected as the current detection signal Vin according to the relationship VF6<Vfl<V[2.

Using the signals detected in this manner, the comparison circuit C determines whether the condition is normal or abnormal. Here, the first reference voltage VcO and the second reference voltage Vcl are expressed as follows: V f3<VcO<V fl<Vcl<V
The relationship is set to f2.

That is, the current detection signal Vin is equal to the first reference voltage Vc.
0 and the second reference voltage Vcl, each filament f1. It is determined that a normal preheating current is flowing through f2 and a normal signal is output, and when a current detection signal Vin outside this range is detected, the preheating circuit section A
It is possible to determine that the connection state between ft, Af2 and each filament fl, f2 is abnormal and output an abnormal signal.

Here, each mode of the current detection signal Vin will be explained.

(When the current detection signal Vf3 is input manually) The output of the comparator C1 is the zero voltage of the current detection signal Vf3 and the first reference voltage V.
When compared with the substantially zero voltage of cO, it becomes "H level" due to the relationship of VF6<VcO. - On the other hand, the output of comparator C2 is
Comparing the zero voltage of the current detection signal Vf3 and the predetermined voltage of the second reference voltage Vcl, the result is determined by the relationship of VF6<Vcl.
It becomes "L level".

Then, these outputs are inputted to the OR circuit OR, and "H"
An output signal of level "" is generated. This is considered an abnormal signal.

When receiving both the "H level" abnormal signal and the "H level" timer signal output from the timer circuit T after a predetermined period of time has elapsed from the start of operation of the reference voltage generation circuit E, A
The output of the ND circuit AND becomes the "I" level, the transistor Tr is turned on, and the relay Ry is driven.
Contact point S1. S2 is turned off and the discharge lamp is turned off.

At this time, since the lighting circuit continues to operate,
The control circuit section and the attachment detection section X can maintain their operating states. Further, by continuously generating the abnormality signal as the discharge lamp goes out, it is possible to maintain the off state of the discharge lamp.

(When the current detection signal V "2" is input) The output of the comparator CI is the voltage of the current detection signal Vf2 and the first reference voltage Vc.
When compared with the substantially zero voltage of O, it becomes "L level" due to the relationship of VcO<VF6. - On the other hand, the output of the comparator C2 compares the voltage of the current detection signal Vf2 and the predetermined voltage of the second reference voltage Vcl, and the output of the comparator C2 is "I
"level".Then, these outputs are outputted to the OR circuit O.
R is manually inputted, and an output signal of ``H level'' is generated.This is taken as an abnormal signal.The following explanation is the same as the previous one, so the explanation will be omitted.

(When the current detection signal Vfl is input) The output of the comparator CI is the voltage of the current detection signal Vfl and the first reference voltage Vc.
When compared with the substantially zero voltage of O, it becomes "L level" due to the relationship of VcO<VF6. - On the other hand, the output of the comparator C2 becomes "L level" by comparing the voltage of the current detection signal Vfl and the predetermined voltage of the second reference voltage Vcl due to the relationship of Vfl<Vcl. Then, these outputs are inputted to the OR circuit OR, and an "L level" output signal is generated. This is considered a normal signal.

While receiving the normal signal of "L level" 1, the AN
The output of the D circuit AND is always at "L level", the transistor Tr is off, the relay Ry is not driven, and the contacts S1. S2 is maintained in the on state, and the discharge lamp continues to be lit.

Note that the timer circuit T uses the current detection signal Vf2 when it is necessary to set the preheating current at startup to a large value for a predetermined period.
This is provided to prevent an abnormality from being detected as an error, and the operation of the attachment detection section X is stopped for a predetermined period after the power is turned on. Therefore, it goes without saying that it may be omitted if it is not particularly necessary.

Next, FIG. 3 shows a second embodiment of the present invention, in which the same components as those in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

The configuration differs from the first embodiment in that the lighting circuit section is composed of a dimming type ballast including a dimmer Q, and that the current detection elements 1a and lb are connected between both filaments (1 and f2). Detection transformer T1 that detects the voltage (between Eero and Harney). T
2.

Here, each of the detection transformers Tl, T2 has a preheating winding N5. The reason why it can be detected because it is connected to both ends of N6 is that any preheating transformer has internal impedance.

Therefore, depending on the connection state of the filaments fl and f2, the preheating winding N5. N
The voltage generated across the terminal 6 changes, and by detecting this change in voltage, the same effects as in the first embodiment can be obtained.

Note that the configuration of the lighting circuit section and relay is not limited to this embodiment, and depending on the lighting circuit section, a relay or an alternative opening/closing means may be provided at any location where the discharge lamp is turned off. It's also good.

In addition, it is not limited to a device that turns off a discharge lamp when an abnormal wearing condition is detected as shown in this example, but a device that notifies the user of an abnormality by blinking a light source or by providing an indicator light. In short, any means may be used as long as it can prevent the filaments from being used without any knowledge in a state where the preheating current does not flow normally to each filament.

Furthermore, it goes without saying that the number of discharge lamps is not limited to one as shown in this embodiment, and that a plurality of discharge lamps may be used.

〔Effect of the invention〕

As described above, the present invention includes a mounting detection section that detects an abnormal connection state between a preheating circuit section and the filament, and a control circuit section that substantially limits the output of the lighting circuit section based on the output of the mounting detection section. The remarkable effect of this feature is that it is possible to prevent short lifespans of discharge lamps caused by continuous use of discharge lamps in conditions where preheating current does not flow normally to each filament. It is something that plays.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram showing the basics of the present invention, FIG. 2 is a circuit configuration diagram showing a first embodiment of the invention, and FIG. 3 is a circuit diagram showing a second embodiment of the invention. 4 to 6 are operation waveform diagrams for explaining the same operation as above, and FIG. 7 is a circuit configuration diagram showing a conventional example. AC...power supply, A...lighting circuit section, fl, f2...
・Filament, L...discharge lamp, /M1. Ar1...
- Preheating circuit section, X... mounting detection section, D... control circuit section. Figure 1 Figure 2 A Figure 3

Claims (1)

[Claims] (1) a power source, a lighting circuit unit coupled to the power source, a discharge lamp having a filament that is lit by receiving power from the lighting circuit unit, and a preheating circuit unit that supplies preheating current to each of the filaments; an attachment detection unit that detects an abnormal connection state between the preheating circuit unit and the filament;
A discharge lamp lighting device comprising: a control circuit section that substantially limits the output of the lighting circuit section based on the output of the attachment detection section.