JP3399024B2 - Discharge lamp lighting device for continuous dimming - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to dimming a fluorescent lamp with a low light flux.
Suitable for lightingContinuousDischarge lamp lighting device for dimming
Things. [0002] 2. Description of the Related Art FIG. 4 shows a conventional fluorescent lamp lighting control system.
It is a circuit diagram. Hereinafter, the circuit configuration will be described.
The AC power supply Vs is connected to a capacitor Cs for noise removal and a transformer.
Connected to the AC input terminal of the full-wave rectifier circuit DB
Have been. The DC output terminal of the full-wave rectifier circuit DB
Dacta L₁ And a series circuit of MOS transistor Q are connected.
Have been. Both ends of the MOS transistor Q
Do D₁ Through the capacitor C₁ Is connected. Con
Densa C₁ At both ends of the resistor R₁ , R_Two Series circuit
The columns are connected. MOS transistor Q is a chopper
On / off control is performed by the control circuit 1, and the MOS transistor
When the transistor Q is turned on, the inductor L₁ Current
It flows and energy is stored. Also, MOS transistors
When the transistor Q is turned off, the inductor L₁ Accumulated in
Inductor L by energy₁ Induced voltage is generated at both ends of
And is superimposed on the output voltage of the full-wave rectifier circuit DB,
Aether D₁ Through the capacitor C₁ Is charged. this
The capacitor C₁ Boosts full-wave rectified voltage
The obtained DC voltage is obtained. This voltage is the resistance R₁ , R_TwoTo
The voltage is further divided and detected by the chopper control circuit 1,
The MOS transistor Q is set so that the output voltage is constant.
Feedback controlled. With the above circuit,
The upper circuit is configured. Next, the configuration of the inverter circuit will be described.
I do. Capacitor C₁ The transistor Q₁ ,
Q_Two Are connected in parallel. Transistor Q
₁ At both ends are coupling capacitors C_Two Through
And the capacitor C_Three And inductor L_Two Connected in series
Have been. Capacitor C_Three At both ends of the discharge lamp FL
The power supply side terminal of the filament is connected. Discharge lamp F
A capacitor C is connected between the non-power side terminals of the filament L.
_FourIs connected. Transistor Q₁Base Emi of
The inductor L_Two The secondary winding of the resistor R_Three Through
And a resistor R_Four Are connected in parallel
I have. Transistor Q_Two From the control circuit 2
The separately-excited control signal is input. Transistor Q_Two Is a system
Is turned on / off by a separate excitation control signal from the control circuit 2.
Transistor Q₁ Is the inductor L_Two From the secondary winding
Is self-excited by the feedback signal. This allows
Transistor Q₁ , Q_Two Are turned on and off alternately,
Kuta L_Two And capacitor C_ThreeSeries resonance
C_Three Discharge lamp FL is turned on by resonance voltage generated at both ends of
I do. FIG.
A dimming signal as shown in (a) and (b) is transmitted through the transmission line 3.
Transmitted. This dimming signal is a constant frequency rectangle
It consists of a wave signal and has a variable duty. Transmission line
3 is connected to the light emitting element LED of the photocoupler PC.
The light receiving element Q of the photocoupler PC_Three In
The control circuit 2 is connected. In the control circuit 2, the dimming control
Discharge according to dimming signal output from controller 4
An inverter circuit so as to make the output light flux of the lamp FL variable.
Transistor Q_Two Is controlled. FIG. 6 shows a conventional light output characteristic. Figure
The middle and horizontal axes show the dimming signal duty and the vertical axis shows the light output.
ing. As shown in FIG. 6, a conventional dimming discharge lamp point
In the lighting device, the dimming transmitted from the dimming controller 4 is performed.
The optical output changes linearly with the duty of the optical signal
At the same time, turn off the light in the low luminous flux area (standby in the preheating mode).
Configuration was adopted. [0006] SUMMARY OF THE INVENTION The conventional system as described above
In the control method, the low light flux dimming lighting state near the lower limit of the light flux
When setting the light output in the
May shift to the preheating mode,
Setting was not easy. [0007] The present invention has been made in view of such a point.
The purpose is to reduce the luminous flux near the lower limit.
Easy setting of light output in low luminous flux dimming lighting state
To improve user experience
It is in. [0008] According to the present invention, the above
In order to solve the above problem, as shown in FIG.
Dimming control controller with near continuous output in the range
A roller 4 having an output from the light control controller 4
The output light flux of the fluorescent lamp FL is changed according to the dimming signal
Continuous dimmable discharge lamp lighting device
Therefore, as shown in FIG.
Output area, a first area which is an unlighted area, an output light flux
The second area, which is the lower limit area, is out of the lower limit area of the output light flux.
A control circuit for dividing the lighting state into a third area having a high power flux
Output for the operation of the dimming controller 4
The change in the luminous flux is greater in the second region than in the third region.
All set gentlyThereby adjusting the second area.
Output light flux changes almost in response to light controller operation
The second region and the first region
The output light flux changes discontinuously between
The output light flux changes continuously between the region and the third region
likeIt is characterized by having done. [0009] According to the present invention, the dimming control controller 4 is connected.
For a subsequent output, a first area, which is a light-off area, an output light
The second area, which is the lower limit area of the light flux, is lower than the lower limit area of the output light flux.
Control to divide the lighting state into a third area where the output light flux is high
Circuit for controlling the operation of the dimming control controller 4.
The change of the power light flux is applied to the third area in the second area.
Set loosely compared toBy doing so, the second area
The output luminous flux changes little with the operation of the dimming controller.
And the second region and the first region.
The output light flux changes discontinuously between the zones, and the second
The output light flux changes continuously between the third area and the third area.
LikeLow light flux dimming light near the lower limit of the light flux
The light output can be easily set in the
It can improve the usability of the user.
You. [0010] FIG. 2 is a circuit diagram of a main part of an embodiment of the present invention.
You. Duty transmitted from dimming controller 4
When the variable light control signal is at the high level,
The light emitting element LED of the plastic PC generates an optical signal,
Light receiving element Q of plastic PC_Three Is in a conductive state.
A resistor R is connected to both ends of the sensor C._FiveAre connected in parallel. Also before
When the light control signal is at a low level, the photocoupler P
Since the light emitting element LED of C does not generate an optical signal,
Light receiving element Q of coupler PC_ThreeBecomes non-conductive, and the resistance R
_FiveIs separated from both ends of the capacitor C. At this time,
Capacitor C is a resistor R₆ Line of power supply voltage Vcc through
Charged from. Period during which the dimming signal is at High level
Is long, the capacitor C becomes the resistance R_FiveWhen discharged through
Since the interval becomes long, the voltage V of the capacitor C₁ Is low
Also, if the period during which the dimming signal is at the low level is long,
Capacitor C has resistance R_FiveThe time to be discharged through is short
The voltage V of the capacitor C₁ Will be higher. But
Therefore, according to the duty of the dimming signal,
Voltage V₁ Changes as shown by the solid line in FIG. This con
Voltage V of capacitor C₁ Is the resistance R₇ , R₈ Illustrated via
Is not input to the comparator
Reference voltage for determining ON period of switching element
Has been used as Specifically, the power of the capacitor C
Pressure V₁ Rises, accordingly, the inverter circuit
The on-period of the switching element becomes longer, increasing the output light flux.
It is configured to be great. Here, the circuit shown in FIG.
Corrects the variable duty dimming signal transmitted from controller 4
For this purpose, a constant voltage circuit 5 is provided. This constant voltage cycle
The path 5 is provided near the lower limit of the dimming range, and is used to decode
Provides almost constant brightness regardless of changes in
Output voltage V_Three To keep the lower limit voltage of
is there. The Zener diode ZD of the constant voltage circuit 5 has a resistor.
Anti-R₉ From the power supply voltage Vcc line
The current is flowing, and the both ends correspond to the Zener voltage Vz
Constant voltage is generated. Transistor Q_Five Collector
Is connected to the power supply voltage Vcc line,
Star Q_Five Constant voltage Vz is applied to the base of
And the transistor Q_Five The lower limit of the emitter potential is V_Two = V
z-Vbe. Here, Vbe is the transistor Q_Five
Is the forward voltage drop between the base and the emitter. Now, the voltage V of the capacitor C₁ Is the lower limit
Pressure V_Two Higher than transistor Q_Five Base of
The transistor Q is reverse biased between the emitters.
_Five Is in a cutoff state, and the constant voltage circuit 5₇ ,
R₈ Are separated from the connection point. Accordingly
The output voltage V in this case_Three Is V_Three = V₁ And dimming
Switching of the inverter circuit according to the duty of the signal
The ON period of the switching element changes. Next, the capacitor C
Pressure V₁ Is the lower limit voltage V_Two Lower than
Jista Q_Five Is forward biased between base and emitter
And the transistor Q_Five Operates as an emitter follower circuit
And the transistor Q_Five Of the capacitor C
Voltage V₁ Regardless of V_Two = Vz-Vbe
You. Therefore, the output voltage V_Three Is the lower limit voltage V_Two Solid
And is independent of the change in the duty of the dimming signal.
The on-period of the switching element of the barter circuit is constant.
You. Voltage V of capacitor C₁ Is further reduced, and
When the pressure falls below the level, the level detection circuit 6 operates and the transformer
Jista Q_Four Turn on. As a result, the output voltage V_Three Is
It is fixed to zero level, and the inverter circuit
Become. [0013] Summarizing the above operations, FIG.
The duty of the dimming signal is equal to the voltage V of the capacitor C.₁ And fixed
The lower limit voltage V of the voltage circuit 5_Two Corresponds to point A where
Duty d₁ Is larger than the output voltage V_Three
Is the voltage V of the capacitor C₁ Equal to the duty
d₁ The duty d at which the level detection circuit 6 operates below _Two
Is larger than the output voltage V_Three Is the lower limit voltage V
_Two Fixed to the duty d_Two Below, the output voltage V_Three
Becomes 0. Therefore, light output characteristics as shown in FIG.
It is. It is to be noted that the variable duty dimming signal is
Voltage V₁ Is not a straight line as shown in FIG.
I do not care. Also, the voltage V_Two The change characteristics of
Need not be a constant voltage, and at least the voltage V₁ More strange
If the curve is gradual,
Changes in output light flux in response to changes in
Operation becomes easy. Also, the level detection times
Transistor Q_Four To turn on
Although the preheating mode is configured, the voltage V_Three Output
By adding an integrating circuit with a resistor and a capacitor,
And duty d _Two Changes when turning off
It becomes slow and darkness immediately
It has a function like a so-called fade cut
I can help you. [0015] According to the present invention, in the dimming control range,
Has dimming controller with almost continuous output
And a dimming signal output from the dimming controller.
The output light flux of the fluorescent lamp can be changed according to
In dimmable discharge lamp lighting devices, the dimming control
In response to the continuous output of the roller,
Area, output light flux lower limit area, second area, output light flux lower limit
The lighting state is divided into a third area where the output light flux is higher than the area.
Control circuit to control the dimming controller
The change of the output light beam with respect to the third region
Set slowly compared to the areaBy doing so, the second
Output light flux for the operation of the dimming controller
Is a region where little changes occur, and the second region and
The output light flux changes discontinuously between the first regions, and
The output light beam is continuous between the second area and the third area.
To change toDimmed fluorescent light with low luminous flux
In this case, the light output can be easily set,
There is an effect that it becomes very easy to use as compared with the related art.

[Brief description of the drawings] FIG. 1 is a light output characteristic diagram showing the operation of the present invention. FIG. 2 is a circuit diagram of one embodiment of the present invention. FIG. 3 is an operation explanatory diagram of one embodiment of the present invention. FIG. 4 is a circuit diagram of a conventional example. FIG. 5 is an operation explanatory diagram of a conventional example. FIG. 6 is a light output characteristic diagram showing the operation of the conventional example. [Explanation of symbols] 1 Chopper control circuit 2 Control circuit 3 Dimming signal transmission line 4 Dimming control controller 5 Constant voltage circuit 6 level detection circuit FL fluorescent lamp

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-5597 (JP, A) JP-A-3-49186 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05B 41/39 H05B 41/24 H05B 41/282 H05B 41/392

Claims (1)

(57) Claims 1. A dimming control controller having a substantially continuous output in a dimming control range, and a fluorescent lamp according to a dimming signal output from the dimming control controller. In the discharge lamp lighting device capable of continuously dimming the output light flux, a first area that is an extinguished area and a second area that is an output light flux lower limit area for a continuous output of the dimming controller. A control circuit for dividing a lighting state into a third area having a higher output light flux than the lower limit area of the output light flux, and controlling a change in the output light flux in response to an operation of a dimming control controller in the second area. The second area is set to be more gradual than the area of
Where the output luminous flux hardly changes when the controller is operated.
And a region between the second region and the first region.
The output light flux changes discontinuously, and the second region and the second
The discharge lamp lighting device for continuous dimming , wherein the output luminous flux changes continuously between the three regions .