JP2009054425A - Lighting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting apparatus capable of deeper light control than a conventional one. <P>SOLUTION: A light control circuit 10 adjusts optical output of a light-emitting module M by controlling a DC current Ila supplied from a lighting circuit 9 to the light-emitting module M according to an established light control level. The light control circuit 10 comprises an amplitude control part 11 to adjust the size of the DC current Ila supplied to the light-emitting module M, a PWM control part 12 which supplies intermittently the DC current to the light-emitting module M and adjusts the duty ratio, and a general control part 13 which determines a combination of the size of the DC current Ila adjusted by the amplitude control part 11 and the duty ratio adjusted by the PWM control part 12 according to the light control level. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lighting fixture that includes a light emitting module that emits light when supplied with a direct current, and that can adjust the light output of the light emitting module by controlling the direct current supplied to the light emitting module.

  2. Description of the Related Art Conventionally, various lighting fixtures including a light emitting module that emits light when supplied with DC power (for example, an organic EL element or an LED using a light source) have been provided.

  In this type of lighting fixture, the dimming control of the light emitting module can be performed, for example, by supplying a direct current to the light emitting module intermittently at a predetermined period and a ratio of a period for supplying the direct current to one period. A configuration for adjusting the light output of the light emitting module by performing PWM control for adjusting the duty ratio is known (see, for example, Patent Document 1).

There is also a lighting fixture that employs a dimming method called amplitude control that adjusts the light output of the light emitting module by adjusting the magnitude of the direct current supplied to the light emitting module instead of the PWM control as described above. Are known.
JP 2006-40872 A (Pages 7-8)

  By the way, in a lighting fixture that performs dimming control by amplitude control, when performing dimming with a dimming level of about 0.1% (that is, a dimming ratio of 1: 1000), for example, 0.4 mA to 400 mA. It is necessary to take a wide dynamic range of the adjustable current value, which is difficult to realize.

  On the other hand, in a lighting fixture that performs dimming control by PWM control, when performing deep dimming with a dimming level of about 0.1%, it is necessary to increase the dynamic range of the pulse width when the duty ratio is changed. . Therefore, for example, if the pulse width of one cycle is several ms (several hundred Hz), the pulse width of the current supplied to the light emitting module when the dimming level is 0.1% is several μs (corresponding to several hundred kHz). As a result, it is necessary to use a light-emitting module capable of high-speed switching. If a light-emitting module that does not support high-speed switching is used, a high-frequency component is applied to the light-emitting module when applying a pulse, causing stress. .

  That is, it is technically difficult to perform deep light control with a light control level of about 0.1% with a conventional lighting fixture.

  This invention is made | formed in view of the said reason, Comprising: It aims at providing the lighting fixture which can perform light control deeper than a conventional structure.

  According to the first aspect of the present invention, the light output of the light emitting module is adjusted by controlling the direct current supplied to the light emitting module according to the set dimming level and the light emitting module that emits light when the direct current is supplied. A dimming circuit for controlling the amplitude of the direct current supplied to the light emitting module, and a PWM for intermittently supplying the direct current to the light emitting module and adjusting the duty ratio. And a control unit that determines a combination of the magnitude of the direct current adjusted by the amplitude control unit and the duty ratio adjusted by the PWM control unit according to the dimming level.

  According to this configuration, the overall control unit determines a combination of the magnitude of the direct current adjusted by the amplitude control unit and the duty ratio adjusted by the PWM control unit according to the dimming level. Compared to the conventional configuration in which dimming control is performed by only one of the PWM control, the dynamic range of the current value adjustable in the amplitude control unit is narrowed, and the dynamic range of the pulse width adjustable in the PWM control unit is narrowed However, deep dimming can be realized by using both the amplitude control unit and the PWM control unit together.

  According to a second aspect of the present invention, in the first aspect of the invention, when the overall control unit changes the dimming level within a specified value or more, either the magnitude of the direct current or the duty ratio is selected. When the dimming level changes within a range below the specified value, the other is fixed at a value when the dimming level is the specified value, and only one of them is changed. The combination is determined as described above.

  According to this configuration, depending on whether the dimming level is equal to or higher than the specified value or lower than the specified value, the change target is the magnitude of the direct current adjusted by the amplitude control unit and the duty ratio adjusted by the PWM control unit. Will be switched. Therefore, the overall control unit can be realized with a simple configuration in which the amplitude control unit and the PWM control unit are selectively used according to the dimming level.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the light emitting module has a capacitance component between the electrodes due to the structure in which the light emitting portion is interposed between the opposed planar electrodes, A planar light-emitting module having a predetermined non-light-emitting period that does not emit light immediately after rising, wherein the dimming circuit adjusts a period in which the PWM controller intermittently supplies a direct current to the light-emitting module When the dimming level falls below a lower limit that can be adjusted by the amplitude control unit and the PWM control unit, the overall control unit shortens the cycle by the frequency control unit and occupies one cycle. The ratio of the light emission period is increased.

  According to this configuration, when the dimming level falls below a lower limit that can be adjusted by the amplitude control unit and the PWM control unit, the frequency control unit shortens the period and increases the ratio of the non-light emission period in one period. As a result, the light output of the light emitting module is reduced, so that light control that is deeper than the light control level that can be adjusted by the amplitude control unit and the PWM control unit can be performed.

  In the present invention, the combination of the magnitude of the direct current adjusted by the amplitude controller and the duty ratio adjusted by the PWM controller is determined according to the dimming level. While narrowing the range and narrowing the dynamic range of the pulse width that can be adjusted in the PWM control unit, there is an advantage that light control deeper than the conventional one can be realized.

(Embodiment 1)
As shown in FIG. 1, the lighting fixture of the present embodiment includes a light emitting module M that emits light when supplied with a direct current, a lighting circuit 9 that supplies a direct current Ila to the light emitting module M, and a set dimming control. And a light control circuit 10 that adjusts the light output of the light emitting module M by controlling the direct current Ila supplied from the lighting circuit 9 to the light emitting module M according to the level.

  As shown in FIG. 2, the light emitting module M used in the present embodiment includes a substrate 2 made of a translucent insulating material such as glass, a thin-film anode electrode 3 provided on the substrate 2, and A light emitting layer (light emitting portion) 4 provided on the anode electrode 3, a thin-film cathode electrode 5 sandwiching the light emitting layer 4 between the anode electrode 3, and a sealing layer 6 made of, for example, a silicon resin. The light emitting element 1 is used. Here, the light emitting module M is configured by providing a pair of power supply terminals 7 and 8 electrically connected to the anode electrode 5 and the cathode electrode 6 on the substrate 2 of the light emitting element 1.

  Here, the light emitting layer 4 is an organic thin film that emits light when energized in the thickness direction, and the light emitting element 1 constitutes an organic EL element. The anode electrode 3 is formed of a light-transmitting conductive material such as ITO (Indium Tin Oxide), which is a transparent electrode material, and transmits light generated in the light emitting layer 4 to the substrate 2 side. On the other hand, the cathode electrode 5 is made of a metal (for example, aluminum) thin film, and reflects the light generated in the light emitting layer 4 to the anode electrode 3 side.

  With this configuration, if a direct current is supplied between the anode electrode 3 and the cathode electrode 5 so that the anode electrode 3 becomes an anode and the cathode electrode 5 becomes a cathode, the light from the light emitting layer 4 passes through the anode electrode 3 and the substrate 2. The portion corresponding to the light emitting layer 4 in the substrate 2 emits light in a planar shape. In the present embodiment, the anode electrode 3, the cathode electrode 5, and the light emitting layer 4 are formed smaller than the substrate 2, and the substrate 2 and the light emitting layer 4 are each formed in a rectangular shape whose sides are parallel to each other. The sealing layer 6 is formed to cover the surface and side surfaces of the cathode electrode 5 and the side surfaces of the light emitting layer 4. In the example of FIG. 2, the cathode electrode 5 is formed to be approximately the same size as the anode electrode 3, but the entire area does not overlap the anode electrode 3 in the thickness direction (part of the right end in FIG. 2). 2) are arranged to be shifted to the right in FIG. 2 with respect to the anode electrode 3 so as to protrude from the anode electrode 3. Here, the light emitting layer 4 extends along the end surface (the right end surface in FIG. 2) of the anode electrode 3 so as to exist in the entire region between the facing surfaces of the anode electrode 3 and the cathode electrode 5.

  As shown in FIG. 1, the lighting circuit 9 includes a DC power source E, a series circuit of a switching element Q1, an inductor L1, and a capacitor C1 connected between output terminals of the DC power source E, and a switching element Q1 and an inductor L1. It comprises a so-called buck converter including a diode D1 connected between both ends of a series circuit of an inductor L1 and a capacitor C1 so as to connect the cathode to the connection point side, and a drive circuit D that controls on / off of the switching element Q1. That is, the output voltage of the lighting circuit 9 generated at both ends of the capacitor C1 is controlled in accordance with the on / off of the switching element Q1 by the drive circuit D. The driving circuit D outputs a switching signal S1 in the form of a pulse wave to the switching element Q1, and the switching element Q1 is turned on when the switching signal S1 is at the H level and turned off when the switching signal S1 is at the L level. Here, a field effect transistor (FET) is used as the switching element Q1. The DC power source E may be a full-wave rectified AC output of a commercial power source using a diode bridge.

  Here, the light emitting module M is connected between both ends of the capacitor C1 so that the output voltage of the lighting circuit 9 (the voltage across the capacitor C1) is applied to the light emitting module M. That is, the anode power supply terminal 7 is connected to the anode side output terminal (one end of the capacitor C1) of the lighting circuit 9, and the cathode power supply terminal is connected to the cathode side output terminal (the other end of the capacitor C1) of the lighting circuit 9. 8 is connected.

  The dimming circuit 10 generates a control signal according to the set dimming level, and controls the output of the lighting circuit 9 by outputting this control signal to the drive circuit D. Here, a dimming controller (not shown) is operated to arbitrarily select a dimming level from a plurality of dimming levels set between 0.1% and 100%. A configuration in which a signal is input to the dimming circuit 10 is employed. The dimming signal is, for example, a signal having a pulse waveform of 1 kHz (that is, the period is 1 ms), and represents the dimming level by the pulse width. The dimming circuit 10 generates a control signal according to the dimming level represented by the dimming signal. The dimming ratio when the dimming level is 0.1% is 1: 1000.

  By the way, the light control circuit 10 of this embodiment supplies the direct current Ila to the light emitting module M intermittently with a predetermined period, and the amplitude control part 11 which adjusts the magnitude | size of the direct current Ila supplied to the light emitting module M. In addition, a PWM control unit 12 that adjusts the duty ratio, which is a ratio of a period during which the DC current Ila is supplied for one cycle, and an overall control unit 13 that controls operations of the amplitude control unit 11 and the PWM control unit 12 are provided. The overall control unit 13 determines a combination of the magnitude of the direct current Ila adjusted by the amplitude control unit 11 and the duty ratio adjusted by the PWM control unit 12 according to the set dimming level. The amplitude control unit 11 and the PWM control unit 12 operate according to the magnitude of the direct current Ila and the duty ratio instructed from the overall control unit 13, respectively.

  The amplitude controller 11 detects the DC current Ila supplied to the light emitting module M by monitoring the voltage across the resistor R11 inserted between the negative electrode of the light emitting module M and the capacitor C1, and the detected DC current Ila The drive circuit D is controlled by the control signal so that the size matches the size instructed from the overall control unit 13.

  Hereinafter, the operation of the light control circuit 10 will be described in detail.

  That is, the dimming circuit 10 uses both so-called amplitude control performed by the amplitude control unit 11 and PWM control performed by the PWM control unit 12, thereby deeper than the case of only amplitude control or only PWM control. Dimming is possible.

  Here, the overall control unit 13 fixes the duty ratio adjusted by the PWM control unit 12 to 100% and adjusts the direct current adjusted by the amplitude control unit 11 when the dimming level changes within a predetermined value or more. A combination of the duty ratio and the magnitude of the direct current Ila is determined so that only the magnitude of the current Ila is changed. That is, when the dimming level is equal to or higher than the specified value, the overall control unit 13 uses the amplitude control unit 11 to adjust the light output of the light emitting module M.

  On the other hand, when the dimming level changes within the specified value or less, the overall control unit 13 sets the magnitude of the direct current Ila adjusted by the amplitude control unit 11 to a value when the dimming level is the specified value. The combination of the duty ratio and the magnitude of the direct current Ila is determined so that only the duty ratio that is fixed and adjusted by the PWM control unit 12 is changed. That is, when the dimming level falls below the specified value, the overall control unit 13 uses the PWM control unit 12 to adjust the light output of the light emitting module M.

  Here, as an example, the predetermined value is set to a dimming level of 10%, and the overall control unit 13 performs amplitude control using the amplitude control unit 11 if the dimming level is in the range of 100% (all lighting) to 10%. If the dimming level is within the range of 10% to 0.1%, the PWM control using the PWM control unit 12 is performed.

In short, when the magnitude of the direct current Ila adjusted by the amplitude controller 11 when the dimming level is 100% is I ₀ shown in FIG. 3A, the dimming level is set to 50%. The magnitude of the direct current Ila is adjusted to 0.5I ₀ by the amplitude controller 11 as shown in FIG. 3B, and when the dimming level is set to 10% which is the predetermined value, the direct current Ila the size is adjusted to 0.1I ₀ as shown in FIG. 3 (c) by the amplitude control unit 11. Thus, in the range where the light control level is 10% or more, the light output of the light emitting module M is changed by changing the magnitude of the direct current Ila supplied to the light emitting module M. Here, if the dimming level is 10% or more, the duty ratio adjusted by the PWM control unit 12 is fixed to 100%. Therefore, in each state shown in FIG. 3, the direct current Ila is continuously supplied. The

On the other hand, in the state in the range dimming level below 10%, the dimming level and the magnitude 0.1I ₀ of DC current Ila at a 10% was maintained by the amplitude control unit 11, PWM as shown in FIG. 4 The control unit 12 adjusts the duty ratio. That is, when the light control level is 10%, the duty ratio adjusted by the PWM control unit 12 is 100% as shown in FIG. 4A, whereas the light control level is set to 5%. The duty ratio is adjusted to 50% as shown in FIG. 4B, the direct current Ila is intermittently supplied to the light emitting module M, and the pulse width is 50% of one cycle. When the dimming level is set to 1%, the duty ratio is adjusted to 10% as shown in FIG. 4C, and the pulse width of the direct current Ila supplied to the light emitting module M is 10% of one cycle. Become. Thus, in the range where the light control level is 10% or less, the light output of the light emitting module M is changed by changing the on-duty of the direct current Ila supplied to the light emitting module M.

  Although one cycle of the direct current Ila controlled by the PWM control unit 12 is considered to be 950 μm, for example, it is not limited to this, and any cycle may be used as long as the blinking of the light emitting module M is not visually recognized. It can be set.

  Next, the operation of the lighting circuit 9 when dimming control is performed by the above-described dimming circuit 10 will be described with reference to FIG.

  That is, when the dimming level is set to 100%, the drive circuit D that has received the control signal from the amplitude control unit 11 outputs the switching signal S1 shown in FIG. 5A, thereby turning on and off the switching element Q1. Then, a triangular wave inductor current IL flows through the inductor L1, and the direct current Ila is supplied to the light emitting module M to cause the light emitting module M to emit light. On the other hand, when the dimming level is set to 10%, the drive circuit D that has received the control signal from the amplitude control unit 11 is pulsed more than the switching signal S1 in FIG. 5A as shown in FIG. A switching signal S1 having a small width is output, whereby the on-time of the switching element Q1 is shortened, the inductor current IL is reduced, and the magnitude of the direct current Ila supplied to the light emitting module M is also the direct current Ila in FIG. By making it smaller, the light output of the light emitting module M decreases. When the dimming level is set to 5%, the drive circuit D receiving the control signal from the PWM control unit 12 has the same pulse as the switching signal S1 in FIG. 5B as shown in FIG. The switching signal S1 having a width is intermittently output, whereby the inductor current IL intermittently flows. By supplying the direct current Ila to the light emitting module M intermittently, the light output of the light emitting module M is further increased. Reduce further.

  According to the lighting fixture having the configuration described above, the overall control unit 13 of the dimming circuit 10 combines a combination of the magnitude of the direct current Ila adjusted by the amplitude control unit 11 and the duty ratio adjusted by the PWM control unit 12. Since it is determined according to the dimming level, the dynamic range of the current value that can be adjusted by the amplitude control unit 11 is narrowed compared to the conventional configuration in which the dimming control is performed using only one of the amplitude control and the PWM control, and Deep dimming can be realized while narrowing the dynamic range of the pulse width adjustable by the PWM control unit 12. That is, dimming control in the range where the dimming level is 100% to 10% is possible by setting the dynamic range of the current value adjustable by the amplitude control unit 11 to 0.4 mA to 4 mA, for example. Dimming control in the light level range of 10% to 0.1% is made possible by setting the dynamic range of the pulse width adjustable by the PWM control unit 12 to, for example, several ms to several tens μs. In addition, if the minimum value of the pulse width adjusted by the PWM control unit 12 is increased, the stress applied to the light emitting module M at the time of pulse application can be reduced.

  Further, depending on whether the set dimming level is equal to or higher than a predetermined value or lower than the predetermined value, the object of change in the dimming control is the magnitude of the direct current Ila adjusted by the amplitude controller 11 and the PWM control. The overall control unit 13 can be realized with a simple configuration in which the amplitude control unit 11 and the PWM control unit 12 are selectively used according to the dimming level.

By the way, in this embodiment, when the dimming level is equal to or higher than the specified value, the overall control unit 13 uses the amplitude control unit 11 to adjust the light output of the light emitting module M, and when the dimming level falls below the specified value. Although the PWM controller 12 is used to adjust the light output of the light emitting module M, the relationship between the amplitude controller 11 and the PWM controller 12 may be reversed. That is, when the dimming level changes in a range equal to or greater than the specified value, the magnitude of the direct current Ila is fixed at I ₀ and only the duty ratio is changed, and when the dimming level changes within the range less than the specified value. The combination of the duty ratio and the magnitude of the DC current Ila may be determined so that the duty ratio is fixed to a value when the dimming level is a specified value and only the magnitude of the DC current Ila is changed.

  The light emitting module M is not limited to the one using the organic EL element as the light emitting element 1 as described above, and may be any element that emits light when supplied with a direct current. For example, a light emitting diode is used. It may be.

(Embodiment 2)
As shown in FIG. 6, the lighting fixture of the present embodiment is provided with target value generating means 14 for generating a waveform of the direct current Ila corresponding to the dimming level as a target value in the overall control unit 13, and PWM control. The point which added the frequency control part 15 which adjusts the period which the part 12 supplies the direct current Ila intermittently to the light emitting module M to the light control circuit 10 differs from the lighting fixture of Embodiment 1. FIG.

  The target value generation means 14 uses the pulse waveform of the direct current Ila shown in FIG. 7A supplied to the light emitting module M when fully lit (dimming level 100%) as a basic waveform, and according to the dimming level, By reducing the area per pulse of the basic waveform (area of the hatched portion in FIG. 7A), a waveform that becomes a target value (hereinafter referred to as a target waveform) is generated. In the present embodiment, as indicated by a broken line in FIG. 7, one pulse of the basic waveform is divided into 10 parts in the width direction (that is, the time axis direction) and 10 parts in the height direction (that is, the current intensity axis direction). Each area after division is defined as 1 square, and the area of 1 square is defined as a unit area. That is, since the area per pulse of the basic waveform is 100, the area per pulse of the target waveform can be changed in the range of 1 to 100 if the target waveform can be set in increments of 1 square.

  Here, the overall control unit 13 corresponds to the target waveform generated by the target value generating unit 14, instead of using the amplitude control unit 11 and the PWM control unit 12 differently depending on whether they are greater than or less than the specified values as in the first embodiment. The amplitude control unit 11 and the PWM control unit 12 are used together to control the DC current Ila so that the DC current Ila is supplied to the light emitting module M. That is, since the width of each pulse in the direct current Ila supplied to the light emitting module M can be adjusted by the PWM control unit 12 and the height of each pulse can be adjusted by the amplitude control unit 11, the overall control unit 13. In combination with the amplitude control unit 11 and the PWM control unit 12 according to the combination of the magnitude of the direct current Ila determined according to the target waveform and the duty ratio, the direct current Ila corresponding to the target waveform is supplied to the light emitting module M. It will be.

  Therefore, the integrated value of the direct current Ila supplied to the light emitting module M can be changed according to the area per pulse of the target waveform generated by the target value generating means 14, and as a result, the light emitting module M The light output can be changed. Here, in the present embodiment, the target value generating means 14 can set the target waveform in increments of 1 by adjusting the width and height of the target waveform, and corresponds to the dimming level set in increments of 1%. I can do it. The target value generation means 14 is realized by using, for example, a microcomputer that operates with a basic clock, and can output even a stepped waveform as shown in FIG.

  According to the above configuration, for example, when the dimming level is set to 37%, the target value generating means 14 has a waveform with a height of 10 mm and a width of 3 mm as shown in FIG. By adding a waveform having a height of 7 mm and a width of 1 mm, a waveform formed in a staircase shape is generated as a target waveform. As a result, the area per pulse of the target waveform (the area of the hatched portion) is 37% of the basic waveform, and the integrated value of the direct current Ila supplied to the light emitting module M is 37% when all the lights are on. On the other hand, when the dimming level is set to 1%, the target value generating means 14 generates a waveform having a height of 1 mm and a width of 1 mm as a target waveform as shown in FIG. As a result, the area per pulse of the target waveform (area of the hatched portion) is 1% of the basic waveform, and the integrated value of the direct current Ila supplied to the light emitting module M is 1% when all the lights are on.

  Thus, in the luminaire of this embodiment, the overall control unit 13 generates a target waveform according to the dimming level in the target value generation unit 14 and the magnitude of the direct current Ila adjusted by the amplitude control unit 11. By determining the combination with the duty ratio adjusted by the PWM control unit 12 according to the target waveform, it is possible to perform dimming control at a dimming level of 1%.

  By the way, in the present embodiment, the light emitting module M has the above structure in which the light emitting layer 4 is interposed between the planar anode electrode 3 and the cathode electrode 5 facing each other as a light emitting portion. It consists of a planar light emitting module having a capacitance component between the cathode electrode 5. Therefore, as shown in FIG. 8, even when the voltage Vla is applied to the light emitting module M and the DC current Ila rises, a non-light emission period (light output cannot be obtained) of a predetermined length immediately after the DC current Ila rises. Period). In the present embodiment, this non-light emission period is used to enable deep dimming with a dimming level of less than 1%.

  That is, the overall control unit 13 causes the frequency control unit 15 to cause the PWM control unit 12 to emit light when the dimming level falls below a lower limit value (1% in this case) that can be adjusted by the amplitude control unit 11 and the PWM control unit 12. The period for intermittently supplying the direct current Ila to the module M is shortened to increase the proportion of the non-light emitting period in one period.

  According to this configuration, as shown in FIG. 9B, the dimming level is higher than the ratio of the non-light emission period in the period T when the dimming level is 1% as shown in FIG. The ratio of the non-light emitting period in the period T ′ (<T) when the ratio is less than 1% increases. Therefore, deep light control with a light control level of less than 1% is possible. Specifically, the overall control unit 13 decreases the frequency of the PWM control unit 12 intermittently supplying the direct current Ila to the light emitting module M as the dimming level (less than 1%) decreases. To control. Thereby, as the dimming level (less than 1%) decreases, the ratio of the non-light emitting period in one cycle increases, and the light output of the light emitting module M can be reduced.

  The frequency control unit 15 may be added to the dimming circuit 10 of the first embodiment. In this case, when the dimming level falls below the lower limit (1%) that can be adjusted by the amplitude control unit 11 and the PWM control unit 12 shown in FIG. The period during which the PWM control unit 12 supplies the direct current Ila is shortened to increase the proportion of the non-light emitting period in one period. As a result, deep light control with a light control level of less than 1% becomes possible.

  Other configurations and functions are the same as those of the first embodiment.

It is a schematic circuit diagram which shows the structure of Embodiment 1 of this invention. It is the schematic perspective view partly fractured | ruptured which shows the light emitting module used for the same as the above. The operation is the same as above, where (a) is a light control level of 100%, (b) is a light control level of 50%, and (c) is an operation explanatory diagram when the light control level is 10%. The operation is the same as above, with (a) a dimming level of 10%, (b) a dimming level of 5%, and (c) an operation explanatory diagram when the dimming level is 1%. The operation is the same as above, where (a) is a light control level of 100%, (b) is a light control level of 10%, and (c) is an operation explanatory diagram when the light control level is 5%. It is a schematic circuit diagram which shows the structure of Embodiment 2 of this invention. The operation is the same as above, where (a) is a light control level of 100%, (b) is a light control level of 37%, and (c) is an operation explanatory diagram when the light control level is 1%. It is operation | movement explanatory drawing which shows operation | movement of the light emitting module used for the same as the above. The operation | movement same as the above is shown, (a) is dimming level 1%, (b) is operation | movement explanatory drawing when a dimming level is less than 1%.

Explanation of symbols

3 Anode electrode 4 Light emitting layer (light emitting part)
DESCRIPTION OF SYMBOLS 5 Cathode electrode 10 Dimming circuit 11 Amplitude control part 12 PWM control part 13 General control part 14 Target value production | generation means 15 Frequency control part Ila DC current M Light emitting module T, T 'period

Claims (3)

  A light emitting module that emits light when supplied with a direct current, and a dimming circuit that adjusts the light output of the light emitting module by controlling the direct current supplied to the light emitting module according to a set dimming level The dimming circuit includes an amplitude control unit that adjusts the magnitude of the direct current supplied to the light emitting module, a PWM control unit that intermittently supplies the direct current to the light emitting module and adjusts the duty ratio, and an amplitude control unit. And a general control unit that determines a combination of the magnitude of the direct current adjusted in step 1 and the duty ratio adjusted by the PWM control unit in accordance with the dimming level.   When the dimming level changes within a specified value or more, the overall control unit fixes only one of the magnitude of the direct current and the duty ratio and changes only the other, and the dimming level The combination is determined so as to change only one of them when the value changes within a range equal to or less than the specified value, while fixing the other to a value when the dimming level is a specified value. The lighting fixture according to 1.   The light emitting module is a planar light emitting module having a predetermined non-light emitting period in which a light emitting portion is interposed between opposing planar electrodes and has a capacitance component between the electrodes and does not emit light immediately after the rising of a direct current. The dimming circuit includes a frequency control unit that adjusts a cycle in which the PWM control unit intermittently supplies a direct current to the light emitting module, and the overall control unit controls the amplitude control level of the dimming level. The frequency control unit shortens the cycle to increase the ratio of the non-light emitting period in one cycle when the lower limit value that can be adjusted by the control unit and the PWM control unit is exceeded. The lighting fixture of 2.

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