JP2013008462A - Light emitting device and lighting apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device and a lighting apparatus using the same with which color reproducibility of mixed color light based on a group of plural solid light emitting elements can be enhanced.SOLUTION: A light emitting device has a lighting controller 2 for controlling turn-on of a group L of plural solid light emitting elements, an adder 4 and a divider 5. The lighting controller 2 is provided to every solid light emitting element group L, and each lighting controller 2 comprises a driving circuit 21 for supplying current I to every solid light emitting element group L, a peak current detector 25 for detecting the peak value Ip of the current I supplied to the solid light emitting element group L, and a control circuit 22 for feedback-controlling the driving circuit 21. The adder 4 adds detection results of the peak current detectors 25 to generate a total detection voltage VIpt, the divider divides the total detection voltage VIpt to generate an average detection voltage VIpa for every lighting controller 2, and the control circuit 21 performs the feedback control so that the average detection voltage VIpa is coincident with a reference voltage Vref.

Description

  The present invention relates to a light emitting device and a lighting device using the same.

  2. Description of the Related Art Conventionally, there is a light emitting device that includes a lighting control unit that performs lighting control of three solid light emitting element groups that emit light of different chromaticities (red, green, and blue) for each solid light emitting element group (for example, Patent Documents). 1). In this light-emitting device, the outputs of the three solid-state light-emitting element groups are individually controlled, and the output ratio is controlled to vary the chromaticity of the mixed light by each individual light-emitting element group. There is also a light-emitting device that can change the illuminance (output) and light chromaticity of mixed-color light at the same time to obtain comfortable illumination light.

  In the conventional light emitting device, the lighting control unit includes a drive circuit that supplies a current to the solid-state light emitting element group, and a control circuit that controls the drive circuit. Then, in order to make the mixed color light by each individual light emitting element group have a desired chromaticity, it is necessary to control the output ratio of each individual light emitting element group to coincide with the target output ratio. Therefore, each of the lighting control units performs feedback control so that the current supplied to the solid state light emitting element group becomes a target value set for each. Thereby, the output ratio of each individual light emitting element group matches the target output ratio, and the mixed color light has a desired chromaticity.

JP 2010-176984 A

  As described above, the output ratio of the solid state light emitting element group needs to match the target output ratio in order to make the mixed color light by each individual light emitting element group have a desired chromaticity. However, the current supplied to the solid-state light emitting element group may deviate from the target value due to individual differences in components used for the drive circuit and the control circuit. As a result, the output of the solid light emitting element group varies, and the output ratio of each individual light emitting element group deviates from the target output ratio. For example, when the current supplied to the solid-state light emitting elements is shifted from the target value in the direction of increasing red, decreasing in green, and increasing in blue, the output ratio of each individual light emitting element group is the target output ratio. Will be greatly deviated. As a result, the chromaticity of the mixed color light deviates greatly from the desired chromaticity, and the color reproducibility of the mixed color light is reduced.

  The present invention has been made in view of the above reasons, and an object thereof is to provide a light emitting device capable of improving the color reproducibility of mixed color light by a plurality of solid light emitting element groups, and an illumination device using the same. There is to do.

  The light-emitting device of the present invention includes a lighting control unit that performs lighting control of a plurality of solid-state light-emitting element groups that emit light of different chromaticities, an addition unit, and a division unit, and the lighting control unit includes a plurality of lighting control units. Provided for each of the solid-state light-emitting element groups, each of the plurality of lighting control units includes a drive circuit that supplies power to each of the solid-state light-emitting element groups, and power that each of the drive circuits supplies to the solid-state light-emitting element group And a control circuit that feedback-controls the drive circuit based on the detection result of the detection unit, and the addition unit adds up the detection results of the plurality of detection units to detect the total. The division unit generates a division detection result for each lighting control unit by dividing the total detection result at a predetermined ratio, and outputs the division detection result to each of the lighting control units. The control circuit is self Force has been the divided detection result, characterized in that a feedback control to match the reference voltage set to self.

  The light-emitting device includes a color ratio setting unit that sets a target output ratio of each of the solid-state light-emitting element groups, and the driving circuit generates intermittent currents each having an ON period set based on the target output ratio. The light-emitting element group is supplied, the detection unit detects an amplitude value of a current supplied from the drive circuit to the solid-state light-emitting element group in the on-period, and the addition unit is in the on-period The total detection result is generated by adding the amplitude value of the current flowing through each of the solid state light emitting element groups, and the dividing unit divides the total detection result by the number of the lighting control units. It is preferable to generate a detection result and output the division detection result to each of the lighting control units.

  The light-emitting device includes a color ratio setting unit that sets a target output ratio of each of the solid-state light-emitting element groups, and the division unit divides the total detection result based on the target output ratio, thereby controlling the lighting. Preferably, the division detection result is generated for each unit, and the division detection result is output to each of the lighting control units.

  An illumination device of the present invention includes a lighting control unit that performs lighting control of a plurality of solid-state light emitting element groups that emit light of different chromaticities, an addition unit, and a division unit, and the lighting control unit includes a plurality of lighting control units. Provided for each of the solid-state light-emitting element groups, each of the plurality of lighting control units includes a drive circuit that supplies power to each of the solid-state light-emitting element groups, and power that each of the drive circuits supplies to the solid-state light-emitting element group And a control circuit that feedback-controls the drive circuit based on the detection result of the detection unit, and the addition unit adds up the detection results of the plurality of detection units to detect the total. The division unit generates a division detection result for each lighting control unit by dividing the total detection result at a predetermined ratio, and outputs the division detection result to each of the lighting control units. The control circuit is self The light-emitting device that performs feedback control so that the divided detection result that is applied matches a reference voltage set in itself, a plurality of solid-state light-emitting element groups that are turned on by the light-emitting device, and the light-emitting device are housed. An instrument main body to which the plurality of solid state light emitting element groups are attached is provided.

  As described above, the present invention has an effect that the color reproducibility of the mixed color light by the plurality of solid state light emitting element groups can be improved.

1 is a block configuration diagram of a light emitting device according to Embodiment 1. FIG. (A)-(c) It is a wave form diagram of an electric current. 6 is a block configuration diagram of a light emitting device according to Embodiment 2. FIG. (A)-(c) It is a wave form diagram of a control signal. (A) It is an external view of the illuminating device of Embodiment 3. FIG. (B) It is a bottom view of the illuminating device of Embodiment 6. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a block diagram of a light emitting device 1 according to Embodiment 1 of the present invention.

  The light emitting device 1 of the present embodiment outputs a target output of a solid light emitting element group Lr that emits red light, a solid light emitting element group Lg that emits green light, and a solid light emitting element group Lb that emits blue light. It is turned on at a ratio and irradiated with the mixed color light. The solid light emitting element groups Lr, Lg, and Lb are configured by connecting in series three solid light emitting elements (light emitting diodes) that emit red, green, and blue light. The solid light emitting element groups Lr, Lg, and Lb are referred to as solid light emitting element groups L when they are not individually identified. In addition, although the solid light emitting element group L of this embodiment is comprised by connecting three solid light emitting elements in series, it is comprised by connecting a different number of solid light emitting elements in series and parallel. Also good.

  The light emitting device 1 of the present embodiment is a color that sets the target output ratio of the lighting control units 2r, 2g, and 2b that perform lighting control of the solid light emitting element groups Lr, Lg, and Lb and the solid light emitting element groups Lr, Lg, and Lb. The ratio setting unit 3, the adding unit 4, the dividing unit 5, and the output control unit 6 are included. In the light emitting device 1 according to the present embodiment, the lighting control units 2r, 2g, and 2b supply intermittent currents to the solid light emitting element groups Lr, Lg, and Lb, and control the on period thereof, thereby controlling the solid light emitting element groups Lr, Burst dimming is performed to control the output of Lg and Lb. And lighting control part 2r, 2g, 2b is controlled so that the output ratio of solid light emitting element group Lr, Lg, Lb becomes a target output ratio. The lighting control units 2r, 2g, and 2b have the same configuration. Hereinafter, “r (R)” is appended to the end of the reference to the configuration related to the lighting control unit 2r, and “g (G)” is attached to the end of the reference to the configuration related to the lighting control unit 2g. In the configuration related to the lighting control unit 2b, “b (B)” is added to the end of the code, and the alphabet at the end is omitted when not individually identified.

  The color ratio setting unit 3 of the present embodiment is configured by a microcomputer 31 (hereinafter abbreviated as a microcomputer 31), and a target output ratio of each solid-state light emitting element group L is set in the microcomputer 31. Then, the microcomputer 31 determines the ON period of the current I that each lighting control unit 2 supplies to the solid state light emitting element group L based on the target output ratio, and instructs each lighting control unit 2. Each lighting control unit 2 supplies the individual light emitting element group L with the current I controlled so that the ON period of the current I becomes a value instructed by the microcomputer 31.

  Next, a specific configuration and control of the lighting control unit 2 will be described. The lighting control unit 2 includes a drive circuit 21, a control circuit 22, an error amplifier 23, a current detection unit 24, and a peak current detection unit 25.

  The drive circuit 21 turns on the solid light emitting element group L by supplying a current I to the solid light emitting element group L.

  The control circuit 22 controls the current I by controlling the drive circuit 21. As shown in FIGS. 2A to 2C, the currents Ir, Ig, and Ib are constituted by intermittent currents that repeat an on period and an off period. Based on instructions from the microcomputer 31, the control circuits 22r, 22g, and 22b control the on periods Ton1r, Ton1g, and Ton1b in the period T1.

  The current detection unit 24 detects the current I supplied from the drive circuit 21 to the solid state light emitting element group L, and outputs the detection result to the peak current detection unit 25.

  The peak current detection unit 25 acquires the amplitude value of the current I in the on period Ton1 (hereinafter referred to as the peak value Ip) from the detection result of the current detection unit 24, and generates a detection voltage VIp according to the peak value Ip. And output to the adder 4. The current detection unit 24 and the peak current detection unit 25 correspond to the detection unit of the present invention.

  The adding unit 4 generates a total detection voltage VIpt (= VIpr + VIpg + VIpb) obtained by adding the detection voltages VIpr, VIpg, VIpb output from the peak current detection units 25r, 25g, 25b, and outputs the total detection voltage VIpt.

  The dividing unit 5 of the present embodiment includes a voltage divider 51 and equally divides the total detection voltage VIpt output from the adding unit 4 by the number of lighting control units 2 (3 in the present embodiment). That is, the voltage divider 51 generates an average detection voltage VIpa (− = (VIpr + VIpg + VIpb) / 3) that is an average value of the detection voltages VIp. Then, the voltage divider 51 outputs the generated average detection voltage VIpa to each error amplifier 23. The average detection voltage VIpa corresponds to the division detection result of the present invention.

  The voltage divider 51 and the output control unit 6 are connected to the input terminals of the error amplifiers 23, and the average detection voltage VIpa output from the voltage divider 51 and the reference voltage Vref output from the output control unit 6 are connected. Applied. This reference voltage Vref corresponds to the target value of the peak value Ip of each current I. Each error amplifier 23 compares the average detection voltage VIpa with the reference voltage Vref and outputs the comparison result to the control circuit 22.

  Each control circuit 22 controls the on period Ton1 of the current I based on an instruction from the microcomputer 31 as described above, and performs feedback control of the peak value Ip of the current I based on the output of the error amplifier 23.

  Even if the on period Ton1 of each current I is controlled as instructed by the microcomputer 31, if the relative variation occurs in the peak value Ip of each current I, the output ratio of each solid-state light emitting element group L is compared with the target output ratio. It will shift. As a result, the mixed color light by each solid-state light emitting element group L differs from the desired chromaticity.

  However, in the present embodiment, each lighting control unit 2r, 2g, 2b uses the average value (average detection voltage VIpa) of the peak value Ip of each current I as a detection result, and the peak values Ipr, Ipg of the currents Ir, Ig, Ib. , Ipb feedback control. That is, since the average value of the peak value Ip of each current I is controlled to be the reference voltage Vref, the relative variation of the peak value Ip of each current I is reduced. Thereby, the deviation of the output ratio of each individual light emitting element group L with respect to the target output ratio is reduced, and the color reproducibility of the mixed color light by each solid light emitting element group L is improved.

  Furthermore, by performing feedback control of the peak value Ip of each current I using the average detection voltage VIpa as a detection result, the variation of the peak value Ip of each current I with respect to the reference voltage Vref is made uniform.

  In this embodiment, if the reference voltage Vref output from the output control unit 6 is changed, the peak value Ip of each current I is changed by feedback control. That is, only by changing the reference voltage Vref, the output can be changed in a state where the chromaticity of the mixed color light by each individual light emitting element group L is maintained, so that it is easy to adjust the output of the mixed color light.

  In the present embodiment, the error amplifier 23 is provided for each lighting control unit 2, but the error amplifier 23 is provided as one, and the comparison result between the average detection voltage VIpa and the reference voltage Vref is obtained as a control circuit 22r, 22g, You may comprise so that it may output to 22b. As a result, the number of error amplifiers 23 can be reduced, and the configuration can be simplified.

  In the present embodiment, the peak values Ipr, Ipg, Ipb of the currents Ir, Ig, Ib are controlled to be constant, but may be controlled to be different from each other. In this case, a voltage dividing circuit or an amplifier circuit is provided between the error amplifier 23 and the voltage divider 51, and the average detection voltage VIpa is fluctuated at a predetermined ratio and input to the error amplifier 23. Thereby, the peak values Ipr, Ipg, Ipb of the currents Ir, Ig, Ib can be controlled to be different from each other.

  Further, in the present embodiment, the mixed light is emitted by the solid light emitting element group Lr that emits red, the solid light emitting element group Lg that emits green, and the solid light emitting element group Lb that emits blue. You may use the solid light emitting element group L which irradiates another color. For example, you may use the solid light emitting element group L which irradiates white of high color temperature instead of blue. Further, the present invention is not limited to the mixed color light by the three-color solid-state light emitting element group L, and may be configured to irradiate mixed color light having different numbers of colors.

(Embodiment 2)
FIG. 3 shows a block configuration diagram of the light emitting device 1 of the present embodiment. In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1, and description is abbreviate | omitted.

  In the light emitting device 1 of the present embodiment, the lighting control units 2r, 2g, and 2b supply a direct current (steady current) to the solid light emitting element groups Lr, Lg, and Lb and control the amplitude thereof, thereby controlling the solid light emitting element group Lr. , Lg, and Lb are controlled in amplitude dimming. And lighting control part 2r, 2g, 2b is controlled so that the output ratio of solid light emitting element group Lr, Lg, Lb becomes a target output ratio.

  The color ratio setting unit 3 according to this embodiment includes a microcomputer 31 and reference voltage generation units 32r, 32g, and 32b.

  The reference voltage generation unit 32 uses the control voltage V1 output from the output control unit 6 as a power source, and generates reference voltages VrefR, VrefG, and VrefB based on control signals S1r, S1g, and S1b output from the microcomputer 31.

  As shown in FIGS. 4A to 4C, the control signals S1r, S1g, and S1b are composed of PWM signals, and the microcomputer 31 is configured to turn on the control signals S1r, S1g, and S1b based on the target output ratio. Ton2r, Ton2g, and Ton2b are determined. Specifically, in the microcomputer 31, the period T2 corresponds to the total output of each individual light emitting element group L, and the ratio of the on periods Ton2r, Ton2g, Ton2b is equal to the target output ratio of the solid light emitting element groups Lr, Lg, Lb. The on periods Ton2r, Ton2g, and Ton2b are determined so as to be. Therefore, Ton2r + Ton2g + Ton2b = T2.

  Then, the reference voltage generation unit 32 generates a reference voltage Vref (= V1 × Ton2 / T2) obtained by smoothing (dividing) the control voltage V1 using the control signal S1. Then, the reference voltage generation units 32r, 32g, and 32b output the generated reference voltages VrefR, VrefG, and VrefB to the error amplifiers 23r, 23g, and 23b. That is, the control voltage V1 corresponds to the total output of each individual light emitting element group L, and the reference voltages VrefR, VrefG, and VrefB are generated by dividing the control voltage V1 by the target output ratio. Therefore, the ratio of the reference voltages VrefR, VrefG, and VrefB matches the target output ratio of the solid state light emitting element groups Lr, Lg, and Lb. The reference voltages VrefR, VrefG, and VrefB are target values for the amplitudes of the currents Ir, Ig, and Ib supplied to the solid-state light emitting element groups Lr, Lg, and Lb.

  The dividing unit 5 according to the present embodiment includes smoothing units 52 r, 52 g, and 52 b, and each is connected to the output terminal of the adding unit 4. The current detection unit 24 is connected to the input terminal of the addition unit 4, and the detection voltages VI1r, VI1g, and VI1b detected by the current detection units 24r, 24g, and 24b are input. The detection voltages VI1r, VI1g, and VI1b correspond to the amplitude values of the currents Ir, Ig, and Ib. The current detection unit 24 corresponds to the detection unit of the present invention. Then, the adding unit 4 generates a total detection voltage VIt obtained by adding the detection voltages VI1r, VI1g, and VI1b, and outputs the total detection voltage VIt to the smoothing units 52r, 52g, and 52b.

  Each smoothing unit 52 includes a follower 521, resistors R1 and R2, a capacitor C1, and a switching element Q1. A follower 521, resistors R1 and R2, and a switching element Q1 are connected in series, and a capacitor C1 is connected in parallel with a series circuit including the resistor R2 and the switching element Q1. The input terminal of the follower 521 is connected to the adder 4 and is applied with the total detection voltage VIt. The switching element Q1 is composed of an n-channel MOSFET, and is interposed between the resistor R2 and the ground. The gate of the switching element Q1 is connected to the microcomputer 31, and is turned on / off based on the control signal S1, thereby conducting / blocking between the resistor R2 and the ground. Accordingly, a detection voltage VI2 (= VIt × Ton2 / T2) is generated between both ends of the capacitor C1 by smoothing (dividing) the total detection voltage VIt according to the ON period Ton2 with respect to the period T2 of the control signal S1.

  The control signal S1 output from the microcomputer 31 to the switching element Q1 is the same as the control signal S1 output from the microcomputer 31 to the reference voltage generation unit 32 described above. That is, the smoothing units 52r, 52g, and 52b divide the total detection voltage VIt by the target output ratio using the control signals S1r, S1g, and S1b, thereby detecting the detection voltages VI2r, VI2g, VI2b is generated. Therefore, the ratio of the detection voltages VI2r, VI2g, and VI2b matches the target output ratio of the solid-state light emitting element groups Lr, Lg, and Lb. Then, the smoothing units 52r, 52g, and 52b output the generated detection voltages VI2r, VI2g, and VI2b to the error amplifiers 23r, 23g, and 23b. The detection voltages VI2r, VI2g, and VI2b correspond to the division detection result of the present invention.

  Each error amplifier 23 outputs a difference between the above-described reference voltages VrefR, VrefG, VrefB and the detection voltages VI2r, VI2g, VI2b to the control circuit 22.

  Each control circuit 22 performs feedback control of the amplitude values of the currents Ir, Ig, and Ib so that the detection voltages VI2r, VI2g, and VI2b coincide with the reference voltages VrefR, VrefG, and VrefB.

  As described above, in this embodiment, the detection voltages VI2r, VI2g, and VI2b obtained by dividing the total output (total detection voltage VIt) of each individual light emitting element group L by the target output ratio are feedback-controlled as detection results. The total detection voltage VIt includes errors of the detection voltages VI1r, VI1g, and VI1b with respect to target values (reference voltages VrefR, VrefG, and VrefB), and the errors are also divided by dividing the total detection voltage VIt. That is, the detection voltages VI2r, VI2g, and VI2b include values obtained by averaging the errors of the detection voltages VI1r, VI1g, and VI1b with respect to the target values (reference voltages VrefR, VrefG, and VrefB). Then, feedback control is performed so that the detection voltages VI2r, VI2g, and VI2b coincide with the reference voltages VrefR, VrefG, and VrefB. Variation is reduced. Thereby, the color reproducibility of the mixed color light by each individual light emitting element group L can be improved.

  Furthermore, by performing feedback control using the detection voltages VI2r, VI2g, and VI2b, variations in the detection voltages VI1r, VI1g, and VI1b with respect to the reference voltages VrefR, VrefG, and VrefB can be made uniform.

  In the present embodiment, only the control voltage V1 output from the output control unit 6 is changed, and the values of the reference voltages VrefR, VrefG, and VrefB are changed while maintaining the ratio (target output ratio). That is, only the output can be changed in a state where the chromaticity of the mixed color light by each individual light emitting element group L is maintained only by changing the control voltage V1, and the output adjustment of the mixed color light becomes easy.

  In the present embodiment, as shown in FIGS. 4A to 4C, control is performed so that the output of the solid light emitting element Lr is the largest and the output of the solid light emitting element Lb is the smallest (Ton2r> Ton2g > Ton2b), but is not limited to this. For example, as shown by broken lines in FIGS. 4A to 4C, control is performed so that the output of the solid light emitting element Lb is the largest and the output of the solid light emitting element Lr is the smallest (Ton2b> Ton2g> Ton2r). May be.

(Embodiment 3)
The external view of the illuminating device 10 of this embodiment is shown to Fig.5 (a) (b).

  The illuminating device 10 of this embodiment is comprised by the downlight, and has accommodated the light-emitting device 1 of Embodiment 1 or 2 in the inside of the cylindrical instrument main body 11. FIG. Further, as shown in FIG. 5 (b), a plurality of solid state light emitting elements are mounted on the mounting substrate 12 provided inside the instrument body 11, thereby constituting the solid state light emitting element groups Lr, Lg, and Lb. The solid light emitting element groups Lr, Lg, and Lb are controlled to be turned on by the light emitting device 1. In addition, a translucent panel 13 is provided so as to cover the opening of the instrument body 11, and the mixed color light by the solid light emitting element groups Lr, Lg, and Lb is irradiated to the outside through the translucent panel 13.

  Since the illuminating device 10 of the present embodiment includes the light emitting device 1 of the first or second embodiment, the same effects as those of the first or second embodiment can be obtained, and color mixing by the solid light emitting element groups Lr, Lg, and Lb is possible. The color reproducibility of light can be improved.

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Lighting control part 3 Color ratio setting part 4 Addition part 5 Dividing part 6 Output control part 21 Drive circuit 22 Control circuit 23 Error amplifier 24 Current detection part 25 Peak current detection part 51 Voltage divider L Solid state light emitting element group

Claims (4)

A lighting control unit that performs lighting control of a plurality of solid-state light emitting element groups that emit light of different chromaticity, an addition unit, and a division unit,
The lighting control unit is provided for each of the plurality of solid-state light emitting element groups,
Each of the plurality of lighting control units,
A drive circuit for supplying power to each of the solid-state light emitting element groups;
A detection unit for detecting power supplied to the solid-state light emitting element group by each of the drive circuits;
A control circuit that feedback-controls the drive circuit based on the detection result of the detection unit;
The addition unit generates a total detection result by adding the detection results of the plurality of detection units,
The division unit generates a division detection result for each lighting control unit by dividing the total detection result at a predetermined ratio, and outputs the division detection result to each of the lighting control units,
The light emitting device, wherein the control circuit performs feedback control so that the division detection result output to the control circuit matches a reference voltage set to the control circuit. A color ratio setting unit for setting a target output ratio for each of the solid-state light emitting element groups;
The drive circuit supplies the solid-state light emitting element group with intermittent currents each having an on period set based on the target output ratio.
The detection unit detects an amplitude value of a current supplied from the drive circuit to the solid-state light emitting element group in the ON period,
The adding unit generates the total detection result by adding the amplitude value of the current flowing through each of the solid state light emitting element groups in the ON period,
The division unit generates the division detection result by equally dividing the total detection result by the number of the lighting control units, and outputs the division detection result to each of the lighting control units. Item 2. The light emitting device according to Item 1. A color ratio setting unit for setting a target output ratio for each of the solid-state light emitting element groups;
The division unit generates the division detection result for each lighting control unit by dividing the total detection result based on the target output ratio, and outputs the division detection result to each of the lighting control units. The light-emitting device according to claim 1. The light emitting device according to any one of claims 1 to 3,
A plurality of solid state light emitting element groups to be lit by the light emitting device;
An illuminating device comprising: an instrument body that houses the light emitting device and to which the plurality of solid state light emitting element groups are attached.

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