JP2011028910A - Electrodeless discharge lamp lighting device, and lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp lighting device and a lighting fixture, enabling light control at a desired light control ratio over a wide range, even in case a switching frequency at time-division light control is high. <P>SOLUTION: The electrodeless discharge lamp lighting device, in carrying out shallow light control near a light output at rated lighting (for instance, if a light-control ratio is set at 99% to 80%), controls light by increasing and decreasing high-frequency power supplied by a high-frequency power source circuit 3 during power-on time spans Ton, with a time-division light control circuit 4 in a state fixing the power-on time spans Ton at an upper-limit value Ton-max. Therefore, light control can be continuously carried out at a desired light-control ratio over a wide range even in the case a switching frequency between time spans of power-on and power-off at the time-division light control is high. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrodeless discharge lamp lighting device and a lighting fixture for dimming and lighting an electrodeless discharge lamp.

  Conventionally, there has been an electrodeless discharge lamp lighting device in which an induction coil is disposed close to a bulb in which a discharge gas is sealed, and an electrodeless discharge lamp that emits light by applying a high frequency electromagnetic field to the discharge gas from the induction coil. Is provided.

  As this type of electrodeless discharge lamp lighting device, a high-frequency power supply circuit that generates high-frequency electromagnetic fields by supplying high-frequency power to the induction coil, and dimming the electrodeless discharge lamp by controlling the output of the high-frequency power supply circuit Some have time division dimming circuits.

  In this electrodeless discharge lamp lighting device, by switching the driving frequency of the high frequency power supply circuit in the time-division dimming circuit, the high frequency power supplied to the induction coil is set to an on-period and lighting that sets the magnitude to light the electrodeless discharge lamp. The electrodeless discharge lamp can be dimmed by periodically switching between the off periods set to the size not to be switched and adjusting the ratio of the on period in one cycle (hereinafter referred to as on-duty) ( For example, see Patent Document 1).

JP 2000-353600 A

  By the way, in the electrodeless discharge lamp lighting device having the time-division dimming circuit as described above, a voltage necessary for relighting (re-igniting) the electrodeless discharge lamp when switching from the off period to the on period ( Re-ignition voltage) must be applied for a predetermined period (ignition period). Therefore, if the ratio of the firing period to the switching period for switching between the on period and the off period becomes large, a sufficient off period cannot be secured, and there arises a problem that shallow light control close to the light output at the rated lighting cannot be performed. .

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electrodeless discharge capable of dimming at a desired dimming ratio over a wide range even when the switching frequency in time-division dimming is high. An object is to provide an electric lamp lighting device and a lighting fixture.

  In order to achieve the above object, the invention of claim 1 is an electrodeless discharge lamp lighting device for lighting an electrodeless discharge lamp in which an induction coil is disposed close to a bulb filled with a discharge gas. A high-frequency power supply circuit that supplies high-frequency power that increases or decreases according to the induction coil, an on-period in which the high-frequency power supplied to the induction coil is set to a level at which the electrodeless discharge lamp is lit, and an off period in which the non-lighting level is set to A time-division dimming circuit for dimming and lighting the electrodeless discharge lamp by controlling the driving frequency of the high-frequency power supply circuit so as to be alternately repeated periodically. When the value is reached, the high frequency power supply circuit increases the high frequency power supplied during the ON period.

  According to the first aspect of the present invention, when the ON period of the time division dimming circuit reaches a predetermined upper limit value, the high frequency power supply circuit increases the high frequency power supplied during the ON period. When dimming, the high frequency power supplied by the high frequency power supply circuit during the on period is increased or decreased while the on period is fixed at the upper limit value, or the high frequency power supplied by the high frequency power supply circuit during the on period is supplied to the electrodeless discharge lamp. The light can be adjusted by fixing the level higher than the level at which the light is turned on and increasing / decreasing the ON period within the range of the upper limit value or less. As a result, even when the switching frequency in time-division dimming is high, dimming can be performed with a desired dimming ratio over a wide range.

  According to a second aspect of the present invention, in the first aspect of the invention, the time-division dimming circuit fixes the on-period to the upper-limit value in the on-period after reaching the upper limit value and supplies the high-frequency power supplied from the high-frequency power supply circuit. The electrodeless discharge lamp is dimmed by increasing / decreasing.

  According to a third aspect of the present invention, in the first aspect of the invention, the time-division dimming circuit is configured such that when the on period reaches a predetermined upper limit, the electrodeless discharge lamp lights up the high frequency power supplied by the high frequency power supply circuit during the on period. The electrodeless discharge lamp is dimmed by fixing the level higher than the level to be adjusted and increasing / decreasing the ON period within the range of the upper limit value or less.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the upper limit value is obtained by subtracting a firing period required for re-ignition of the electrodeless discharge lamp from a switching period between the on period and the off period. The period is a value that is 80% or more of the switching period.

  A fifth aspect of the invention is characterized in that, in the invention of any one of the first to fourth aspects, the time division dimming circuit is constituted by a microcomputer.

  In order to achieve the above object, an invention according to claim 6 comprises the electrodeless discharge lamp lighting device according to any one of claims 1 to 5 and a lamp body that supports the electrodeless discharge lamp. And

  According to invention of Claim 6, the lighting fixture which show | plays the effect | action similar to invention of Claims 1-5 can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, even when the switching frequency in time division light control is high, the electrodeless discharge lamp lighting device and lighting fixture which can perform light control with a desired light control ratio over a wide range can be provided.

It is a schematic circuit block diagram which shows Embodiment 1 of the electrodeless discharge lamp lighting device which concerns on this invention. It is a wave form diagram for operation explanation same as the above. It is operation | movement explanatory drawing same as the above. It is a schematic circuit block diagram which shows Embodiment 2 of the electrodeless discharge lamp lighting device which concerns on this invention. It is explanatory drawing explaining operation | movement of Embodiment 3 of the electrodeless discharge lamp lighting device which concerns on this invention. It is a partially broken side view showing an embodiment of a lighting fixture according to the present invention. It is a side view which shows another embodiment of the lighting fixture which concerns on this invention.

(Embodiment 1)
The electrodeless discharge lamp lighting device according to the present embodiment converts DC power supplied from a DC power source E into high-frequency power as shown in FIG. 1 and supplies it to an induction coil 2 disposed close to the electrodeless discharge lamp 1. A high frequency power supply circuit 3 is provided.

  The high-frequency power supply circuit 3 includes a half-bridge type inverter circuit 30 in which a pair of switching elements Q1 and Q2 are connected in series between output terminals of a DC power supply E, a low-side switching element Q2 of the inverter circuit 30, and an induction coil 2. And an inverter control circuit 32 for driving the switching elements Q1, Q2.

  The inverter circuit 30 converts the DC power output from the DC power source E into high-frequency power by alternately switching the pair of switching elements Q1 and Q2 at a high frequency by the drive signal output from the inverter control circuit 32. The resonance circuit 31 includes an inductor Ls and a capacitor Cs connected in series between a connection point of the switching elements Q1 and Q2 and one end of the induction coil 2, and a capacitor Cp connected in parallel to the induction coil 2 and the capacitor Cs. The inverter control circuit 32 increases the high-frequency output (high-frequency power) of the high-frequency power supply circuit 3 if the frequency of the drive signal (drive frequency) approaches the resonance frequency of the resonance circuit 31, and the high-frequency power supply circuit if the frequency is far from the resonance frequency. 3 high frequency output can be reduced.

  Here, the inverter control circuit 32 applies the voltage to the induction coil 2 by gradually lowering the drive frequency to a frequency near the resonance frequency (starting frequency) when the electrodeless discharge lamp 1 that has been turned off is turned on (ignited). Control (sweep control) is performed to turn on (ignite) the electrodeless discharge lamp 1 by gradually increasing the generated voltage (induction coil voltage).

  Further, the electrodeless discharge lamp lighting device of the present embodiment includes a time-division dimming circuit 4 for dimming and lighting the electrodeless discharge lamp 1. The time-division dimming circuit 4 sets the high-frequency power supplied to the induction coil 2 to an on period Ton for setting the level at which the electrodeless discharge lamp 1 is lit (lighting level) and to set to a level for not lighting (non-lighting level). The high frequency power supply circuit 3 (inverter control circuit 32) is controlled so as to periodically and alternately repeat the period Toff, and the dimming ratio is expressed as a ratio when the high frequency power at the rated lighting is 100%. In some cases, control is performed to shorten the on-duty as the dimming ratio decreases (see FIG. 3).

  The inverter control circuit 32 operates so as to switch the frequency (drive frequency) of the drive signal for switching the switching elements Q1, Q2 in accordance with the output of the time division dimming circuit 4. That is, as shown in FIG. 2, when the output of the time division dimming circuit 4 is on (high level), the inverter control circuit 32 switches the switching elements Q1, Q2 at the same drive frequency (for example, 135 kilohertz) as at the time of rated lighting. Is switched on at a driving frequency (for example, 280 kilohertz) sufficiently higher than the rated lighting when the output of the time division dimming circuit 4 is off (low level). By driving the elements Q1 and Q2, the electrodeless discharge lamp 1 is turned off. In the following description, a period required from the start of the on period Ton to the re-ignition of the electrodeless discharge lamp 1 is referred to as an ignition period T1, and a period obtained by subtracting the ignition period T1 from the on period Ton is a lighting period. Called T2 (see FIG. 2).

  Here, as described in the prior art, only the on-duty control in the on-period Ton can secure a sufficient off-period Toff when the ratio of the firing period T1 to the switching cycle for switching between the on-period and the off-period increases. As a result, there arises a problem that the dimming ratio is not as shallow as 100%.

  Therefore, the time-division dimming circuit 4 according to the present embodiment supplies high-frequency power that the high-frequency power supply circuit 3 supplies in the on-period Ton according to the dimming ratio after the on-period Ton reaches a predetermined upper limit value Ton-max. The electrodeless discharge lamp 1 is dimmed by increasing or decreasing it (see FIG. 3). As a method of increasing or decreasing the high-frequency output (high-frequency power) of the high-frequency power supply circuit 3 in the on period Ton, the time-division dimming circuit 4 reduces the drive frequency of the inverter circuit 30 to be lower than the same drive frequency as that during rated lighting. High frequency power is increased by controlling the inverter control circuit 32, and high frequency power is decreased by controlling the inverter control circuit 32 so that the drive frequency of the inverter circuit 30 is higher than the same drive frequency as during rated lighting. The method of letting you adopt can be adopted. Note that the upper limit value Ton-max of the on period Ton is a value in which the period obtained by subtracting the firing period T1 from the switching period (= Ton + Toff) of the on period Ton and the off period Toff is 80% or more of the switching period. desirable. That is, the upper limit value Ton-max may be set so that the relationship Ton-max = (Ton + Toff−T1) / (Ton + Toff) × 100 ≧ 80 is established.

  Thus, according to the present embodiment, in the case where shallow light control close to the light output at the rated lighting is performed (for example, when the light control ratio is 99% to 80%), the time division light control circuit 4 is turned on. Since the high frequency power supplied from the high frequency power supply circuit 3 during the on-period Ton is dimmed while the Ton is fixed at the upper limit value Ton-max, the dimming is performed over a wide range even when the switching frequency in the time division dimming is high. Dimming can be performed continuously at a desired dimming ratio.

(Embodiment 2)
The electrodeless discharge lamp lighting device of the present embodiment includes a step-up chopper circuit 5 that converts AC power supplied from a commercial AC power supply AC as DC power E into DC power as shown in FIG. The circuit 4 is characterized in that a microcomputer is a main component. However, since other configurations including the high frequency power supply circuit 3 are the same as those in the first embodiment, the same components are denoted by the same reference numerals and the description thereof is omitted.

  The step-up chopper circuit 5 includes a diode bridge DB, a choke coil L1, a rectifying diode D1, a switching element Q3, a smoothing capacitor C1, and a chopper control circuit 50 that drives the switching element Q3. However, this type of step-up chopper circuit 5 is well known in the art and will not be described in detail.

  The time-division dimming circuit 4 according to this embodiment includes a microcomputer (hereinafter abbreviated as “microcomputer”) 40 as a main component, dimming signal input terminals 41 and 41 to which dimming signals are input, and dimming signal input. The voltage dividing resistors R1 and R2 connected in series between the terminals 41 and 41 and the capacitor C2 that smoothes the dimming signal resistance-divided by the voltage dividing resistors R1 and R2 are provided. The dimming signal is a rectangular wave signal whose high-level pulse width changes according to the dimming ratio. That is, as the pulse width of the dimming signal becomes longer, the voltage across the capacitor C2 (charge voltage) increases, so the microcomputer 40 captures the voltage across the capacitor C2 and adjusts the target modulation based on the voltage level of the voltage across the capacitor C2. We are looking for the light ratio.

  Then, according to the dimming ratio instructed by the dimming signal, the microcomputer 40 calculates the on-duty duty and the drive frequency finv of the inverter circuit 30 during the on-period Ton, and supplies it to the inverter control circuit 32. The inverter control circuit 32 If the switching elements Q1 and Q2 of the inverter circuit 30 are driven with the on-duty duty given by the microcomputer 40 and the drive frequency finv, the desired over a wide range even when the switching frequency in the time-division dimming is high as in the first embodiment. The light can be adjusted continuously at a light control ratio of.

(Embodiment 3)
Since the electrodeless discharge lamp lighting device of the present embodiment has the same configuration as that of the second embodiment, illustration and description of each component will be omitted.

  The time-division dimming circuit 4 in the present embodiment is turned on as shown in FIG. 5 when performing shallow dimming close to the light output at rated lighting (for example, when the dimming ratio is 99% to 80%). When the period Ton reaches the upper limit value Ton-max, the high frequency power supplied by the high frequency power supply circuit 3 during the on period Ton is fixed to a level higher than the level at which the electrodeless discharge lamp 1 is lit, and the on period Ton is set to the upper limit value Ton. The electrodeless discharge lamp 1 is dimmed by increasing / decreasing within the range of -max or less.

  Thus, in the present embodiment, as in the first or second embodiment, even when the switching frequency in the time-division dimming is high, the dimming can be continuously performed at a desired dimming ratio over a wide range.

  The high frequency voltage (induction coil voltage) applied to the induction coil 2 is resistance-divided and loaded into the microcomputer 40. The microcomputer 40 detects the time until the inflection point where the high frequency voltage gradually increases and becomes saturated. The ignition period T1 is calculated from the time, and the on-duty duty and the drive frequency finv of the inverter circuit 30 in the on-period Ton are calculated according to the calculated ignition period T1 and the dimming ratio indicated by the dimming signal. If given to the inverter control circuit 32, the target dimming ratio can be realized more accurately.

  By the way, as an example of a lighting fixture using the electrodeless discharge lamp lighting device of each of the above embodiments, a lighting fixture A as shown in FIGS. 6 and 7 can be considered. The housing 11 of the luminaire A shown in FIG. 6 supports the electrodeless discharge lamp lighting device (not shown) and the electrodeless discharge lamp 1 inside, and is provided with waterproof performance by sealing the internal space. It is used outdoors as a street light. Further, the casing 11 of the lighting fixture A shown in FIG. 7 is also provided with waterproof performance by sealing the internal space, and is attached to the utility pole 12 or the like and used outdoors as a security light.

DESCRIPTION OF SYMBOLS 1 Electrodeless discharge lamp 2 Induction coil 3 High frequency power supply circuit 4 Time division dimming circuit

Claims (6)

An electrodeless discharge lamp lighting device for lighting an electrodeless discharge lamp in which an induction coil is disposed close to a bulb filled with a discharge gas,
A high-frequency power supply circuit that supplies high-frequency power to the induction coil that increases or decreases according to the drive frequency, an on-period that sets the high-frequency power supplied to the induction coil to a level at which the electrodeless discharge lamp is lit, and an off period that is set to a level that does not light A time-division dimming circuit for dimming and lighting an electrodeless discharge lamp by controlling the driving frequency of the high-frequency power supply circuit so as to periodically and alternately repeat the period,
The time-division dimming circuit increases the high-frequency power supplied by the high-frequency power supply circuit during the on-period when the on-period reaches a predetermined upper limit value.   The time-division dimming circuit adjusts the electrodeless discharge lamp by increasing or decreasing the high-frequency power supplied from the high-frequency power supply circuit while fixing the on-period to the upper limit in the on-period after reaching the upper limit. The electrodeless discharge lamp lighting device according to claim 1.   The time division dimming circuit fixes the high frequency power supplied by the high frequency power supply circuit during the on period when the on period reaches a predetermined upper limit to a level higher than the level at which the electrodeless discharge lamp is lit, and The electrodeless discharge lamp lighting device according to claim 1, wherein the electrodeless discharge lamp is dimmed by increasing / decreasing within a range not exceeding the upper limit value.   The upper limit value is a value in which a period obtained by subtracting an ignition period required for re-ignition of the electrodeless discharge lamp from an on period and an off period is equal to or more than 80% of the switching period. Item 4. The electrodeless discharge lamp lighting device according to any one of Items 1 to 3.   5. The electrodeless discharge lamp lighting device according to claim 1, wherein the time division dimming circuit is configured by a microcomputer.   A lighting fixture comprising: the electrodeless discharge lamp lighting device according to any one of claims 1 to 5; and a lamp body that supports the electrodeless discharge lamp.

Images