JP6489347B2 - Light emitting element lighting device, light emitting module, and lighting device - Google Patents

Description

  The present disclosure relates to a lighting device including a plurality of light emitting modules, and a light emitting module and a light emitting element lighting device used in such a lighting device.

  Patent Document 1 discloses a tile-type flat panel illumination system having a plurality of light emitting units and a communication line that is connected to each light emitting unit and transmits a control signal. In this system, each light emitting unit has a plurality of electrical contacts for power supply. The plurality of light emitting units are electrically connected to each other. Thereby, electric power is transmitted from one light emitting unit to another adjacent light emitting unit. It is disclosed that each light-emitting unit includes a control device, and a plurality of light-emitting units can operate in cooperation by signal communication between the control devices.

Special table 2007-536708 gazette

  In the prior art such as Patent Document 1, the same dimming signal is given to each unit so that each of a plurality of light emitting units (also referred to as “light emitting modules”) emits light with a constant luminance. In PWM dimming generally used as a dimming method, lighting (ON) / extinguishing (OFF) of a light source is repeated in synchronization with a dimming signal. For this reason, the problem of the electromagnetic noise or the acoustic noise accompanying the several light emitting unit repeating lighting / extinction simultaneously may generate | occur | produce.

  The present disclosure provides a novel light-emitting element lighting device that can suppress the occurrence of these noises.

  In order to solve the above-described problem, a light-emitting element lighting device according to an aspect of the present disclosure is a light-emitting element lighting device that is mounted on each light-emitting module in a lighting device including a plurality of light-emitting modules and lights a light-emitting element. A current control circuit that is connected to the light emitting element and modulates a current flowing through the light emitting element based on an input dimming signal; an input interface; and an output interface; and the dimming signal is transmitted via the input interface. A dimming signal processing circuit that receives the dimming signal, inputs the dimming signal to the current control circuit, and changes at least one of an on-time timing and a cycle of the dimming signal and transmits the dimming signal from the output interface. .

  The above aspect may be realized by a system, a method, an integrated circuit, a computer program, or a recording medium. Alternatively, it may be realized by any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

  According to the light emitting element lighting device of the present disclosure, at least one of the on-time timing and the period of the dimming signal received from another light emitting module can be changed and sent to another light emitting module. Since the ratio of light-emitting elements whose ON timing overlaps among a plurality of light-emitting elements can be reduced, generation of electromagnetic noise or acoustic noise can be suppressed.

It is a block diagram showing a schematic structure of a light emitting module in an embodiment of this indication. It is a block diagram which shows the schematic structure of the light emitting element lighting system of Embodiment 1. It is a figure which shows an example of the concrete circuit structure of the light emitting element lighting device 1 in Embodiment 1. FIG. 3 is a timing chart for explaining the operation of the control circuit 50 according to the first embodiment. (A) has shown the output voltage of the 2nd pin of the general purpose microcomputer 601. FIG. (B) shows the voltage of the capacitor 522 applied to the negative input terminal of the comparator 502. (C) shows the reference voltage applied to the positive input terminal of the comparator 502 (the broken line is the voltage of the capacitor 522). (D) shows the output terminal voltage of the comparator 502. 3 is a timing chart showing temporal changes in the light control signal and the current flowing through the light emitting element in the first embodiment. It is a figure which shows an example of the relationship between the light control ratio in Embodiment 2, and the variation | change_quantity of a period timing. It is a timing chart which shows the time change of the electric current which flows through a light control signal and a light emitting element in case a light control ratio is 70%. It is a timing chart which shows the time change of the electric current which flows through a light control signal and a light emitting element in case a light control ratio is 30%. 10 is a timing chart showing temporal changes in the light control signal and the current flowing through the light emitting element in the third embodiment. It is a figure which shows the light emitting module in Embodiment 4. It is a figure which shows an example of the external appearance of the light emitting module in Embodiment 4. It is a block diagram which shows the structure of the illuminating device in Embodiment 5. It is a perspective view which shows an example of the external appearance of the illuminating device in Embodiment 5. FIG. 14 is a flowchart illustrating a lighting operation of a light emitting element according to a sixth embodiment. 10 is a timing chart for explaining a rated current and an abnormality detection current in Embodiment 6. It is a graph showing the example of the voltage-current characteristic (resistance characteristic) of the normal light emitting element and the light emitting element in which the short circuit abnormality has arisen. It is a flowchart which shows the operation | movement which repeats rated mode and detection mode, when the both-ends voltage V1 of the light emitting element 3 in rated mode becomes below the predetermined value V2 lower than rated voltage.

  Prior to describing the embodiments of the present disclosure, knowledge found by the present inventors will be described.

  In an illuminating device having a plurality of light emitting modules, control is generally performed so that a constant current flows through each light emitting element so that each light emitting element emits light with a constant luminance. The same dimming signal is transmitted to each module by signal communication between the light emitting modules, and dimming control is performed.

  As a dimming method, PWM dimming that controls the luminance by repeatedly turning on and off the light source is effective for suppressing a change in chromaticity. In PWM dimming, the light source is switched on / off in synchronization with the dimming signal. For this reason, when the same dimming signal is given to a plurality of light emitting modules, ripples in the power supply current are generated, which may increase electromagnetic noise and acoustic noise. Moreover, since the lighting timings of the plurality of light emitting modules are the same, a problem of heat generation may occur. When the light emitting module and the lighting device are reduced in size or thinned, an increase in noise and heat generation may be a problem. In particular, low heat generation and low noise are particularly required in art museums and museum lighting devices that are required to be thin. Furthermore, if the size of the light emitting module increases in the future, the problem of noise and temperature rise may become more prominent.

  The inventor of the present application has found the above-mentioned problem and studied a configuration for solving this problem. The inventor of the present application can reduce the influence of noise by giving a dimming signal different from others to at least some of the light emitting modules, instead of giving the same dimming signal to each of the plurality of light emitting modules. Focused on. In order to achieve this, a light-emitting element lighting device mounted on a light-emitting module according to an embodiment of the present disclosure includes a dimming signal processing circuit that changes and outputs at least one of an on-time timing and a cycle of a received dimming signal Is provided. The dimming signal processing circuit is electrically connected to the dimming signal processing circuit in another light emitting module. A dimming signal in which at least one of the on-time timing and the cycle is changed is transmitted from one dimming signal processing circuit to another dimming signal processing circuit. Thereby, the situation where the lighting timing of the light emitting element varies depending on the light emitting module is realized.

  FIG. 1 is a block diagram illustrating a schematic configuration of a light emitting module according to an embodiment of the present disclosure. This light emitting module is one of a plurality of light emitting modules constituting the lighting device, and is electrically connected to other light emitting modules via wiring. The light emitting module includes a light emitting element 3 and a light emitting element lighting device 1 for lighting the light emitting element 3. The light emitting element lighting device 1 includes a current control circuit 90 that modulates the current flowing through the light emitting element 3 based on the input dimming signal Si, and a dimming signal processing circuit 70 that inputs the dimming signal S to the current control circuit 90. And have. The dimming signal processing circuit 70 has an input interface IFi and an output interface Ifo. The dimming signal processing circuit 70 receives the dimming signal Si from another device such as a dimming signal processing circuit or a power supply circuit in another light emitting module via the input interface IFi. The dimming signal processing circuit 70 inputs the received dimming signal Si to the current control circuit 90 as the dimming signal S. The dimming signal S may be exactly the same as the dimming signal Si, or the signal level (amplitude) may be changed according to the configuration of the current control circuit 90. The dimming signal S has the same on-time timing (or phase) and period as the dimming signal Si. Here, the “on-time timing” refers to a timing at which the magnitude of the signal changes from a relatively low state (referred to as “off state”) to a relatively high state (referred to as “on state”). In this way, the dimming signal S does not necessarily have the same waveform as the dimming signal Si, but since the on-time timing and period are the same, in the present disclosure, both are the same dimming signal. I think that it is.

  The dimming signal processing circuit 70 further changes at least one of the on-time timing and period of the received dimming signal Si, and sends it out as the dimming signal So from the output interface Ifo. As will be described in detail later, there can be various modes for changing the on-time timing and period. In the present disclosure, the method of processing the dimming signal may be arbitrarily determined as long as the lighting / extinguishing timings of all the light emitting modules constituting the lighting device are not matched.

  With the above configuration, when the dimming signal is transmitted from one light emitting module to another light emitting module, at least one of the on-time timing and the cycle of the dimming signal changes. For this reason, the timing of light emission is shifted by the light emitting module, and the influence of increase in noise and temperature can be reduced.

  Hereinafter, more specific embodiments based on the above basic concept will be described. In the following description, the same or corresponding components are given the same reference numerals. In the following description, the electrical connection is simply referred to as “connection”.

(Embodiment 1)
First, the light emitting element lighting system according to the first embodiment of the present disclosure will be described.

[Constitution]
FIG. 2 is a block diagram showing a schematic configuration of the light emitting element lighting system of the present embodiment. The light emitting element lighting system includes a light emitting element lighting device 1, a power supply circuit 2, and a light emitting element 3. The combination of the light emitting element lighting device 1 and the light emitting element 3 constitutes one light emitting module. The light emitting element lighting device 1 in the present embodiment includes a control power supply circuit 10, a current control circuit 90, a dimming signal processing circuit 70, a current detection circuit 30, and a voltage detection circuit 40. The current control circuit 90 includes a step-down chopper circuit 20, a control circuit 50, and a current command circuit 60.

  The power supply circuit 2 is a circuit that supplies electric power for driving the light emitting element 3. The power supply circuit 2 is connected between, for example, a commercial AC power supply, a direct current (DC) distribution, or a power supply such as a battery, and the light emitting element lighting device 1. The power supply circuit 2 includes, for example, a boost chopper circuit. The power supply circuit 2 rectifies and smoothes the AC voltage supplied from the commercial AC power supply, converts the AC voltage into a DC voltage, and supplies the DC voltage to the light emitting element lighting device 1.

  The light emitting element 3 is, for example, an LED light emitting element such as an organic EL (OLED) light emitting element. The organic EL light emitting device has a structure in which a lower transparent electrode, a light emitting layer, and an upper electrode are stacked on a substrate. The light emitting layer is composed of a plurality of layers such as a hole injection layer, a hole transport layer, an organic light emitting layer, and an electron injection layer. When a voltage is applied between the lower transparent electrode and the upper electrode, holes and electrons are injected into the organic light emitting layer through the corresponding injection layer and transport layer, and recombination occurs. As a result, an excited state is generated, and light is generated in the process of returning to the ground state. In an organic EL light emitting device having a so-called bottom emission structure, light is emitted to the substrate side through a lower transparent electrode. Of the light generated in the light emitting layer, the light directed upward is reflected by the upper electrode, and the light is emitted to the substrate side through the lower transparent electrode. The light emitting element 3 is not limited to an organic EL element, and may be an LED light emitting element made of an inorganic material, for example.

  The control power supply circuit 10 is a circuit that functions as a power supply for the control circuit 50 and the current command circuit 60. The DC voltage applied from the power supply circuit 2 is converted into a voltage used by the control circuit 50 and the current command circuit 60 and output.

  The current detection circuit 30 is a circuit that detects a current flowing through the light emitting element 3. Information on the current detected by the current detection circuit 30 is input to the control circuit 50.

  The voltage detection circuit 40 is a circuit that detects a potential difference (a voltage between both ends) between the positive electrode and the negative electrode of the light emitting element 3. Information on the voltage detected by the voltage detection circuit 40 is input to the current command circuit 60.

  The step-down chopper circuit 20 converts the power supplied from the power supply circuit 2 into the power required by the light emitting element 3 based on the control signal input from the control circuit 50 and outputs the power.

  The current command circuit 60 is a command value of a current to be supplied to the light emitting element 3 based on the voltage across the light emitting element 3 detected by the voltage detection circuit 40 and the lighting signal S output from the dimming signal processing circuit 70. To decide. Information on the command value of the determined current is input to the control circuit 50.

  The control circuit 50 generates a control signal based on the current value detected by the current detection circuit 30 and a signal indicating the current command value input from the current command circuit 60, and sends the control signal to the step-down chopper circuit 20.

  Hereinafter, a more specific configuration of the light-emitting element lighting device 1 will be described with reference to FIG.

  FIG. 3 is a diagram illustrating an example of a specific circuit configuration of the light-emitting element lighting device 1.

  The control power supply circuit 10 includes resistance elements 101 and 102 connected in series between a positive electrode side terminal and a negative electrode side terminal, and a Zener diode 113 connected in parallel to the resistance element 102. With this circuit configuration, the voltage applied between the positive terminal and the negative terminal is divided by the resistance element 101 and the resistance element 102. This divided voltage Vcc becomes a power supply voltage for the control circuit 50 and the current command circuit 60. In this circuit configuration, the Zener diode 113 can prevent the power supply voltage Vcc from exceeding a predetermined value.

  The step-down chopper circuit 20 includes an electrolytic capacitor 201, a switching element 231, a regeneration diode 211, an inductor 221, a capacitor 202, and a drive circuit 232.

  The electrolytic capacitor 201 is connected in parallel to the light emitting element 3, the regeneration diode 211, and the capacitor 202. A DC voltage is applied to the electrolytic capacitor 201 from the power supply circuit 2. The electrolytic capacitor 201 functions as a DC power source that supplies DC power to the light emitting element 3.

  The switching element 231 and the inductor 221 are connected to the light emitting element 3 in series. The switching element 231 is an n-channel enhancement type MOSFET in this example, but may be another type of switching element. The drain of the switching element 231 is connected to the high potential side electrode of the electrolytic capacitor 201. The source of the switching element 231 is connected to one end (high potential side) of the inductor 221. The gate of the switching element 231 is connected to the output terminal of the drive circuit 232.

  Each of the regeneration diode 211 and the capacitor 202 is connected to the light emitting element 3 in parallel. The cathode of the regenerative diode 211 is connected to one end (high potential side) of the inductor 221. The electrode on the high potential side of the capacitor 202 is connected to the other end (low potential side) of the inductor 221.

  The drive circuit 232 is a circuit (gate driver) that inputs a drive voltage (pulse) to the gate of the switching element 231. When the drive voltage is applied from the drive circuit 232, the switching element 231 becomes conductive, and a current flows through the light emitting element 3.

  The step-down chopper circuit 20 switches the switching element 231 at a high frequency by the drive circuit 232. Thereby, the electric power accumulated in the electrolytic capacitor 201 is converted into electric power necessary for the light emitting element 3. The DC voltage applied to the electrolytic capacitor 201, that is, the DC voltage supplied from the power supply circuit 2 is kept constant at 24V, for example. This is a voltage necessary for maintaining lighting of the light emitting element 3 which is an organic EL light emitting element. When an organic EL light emitting element that requires about 5V to 10V for light emitting operation is used, the DC voltage may be about 12V. In addition, when ten organic EL light emitting elements that require about 5 V to 10 V for light emitting operation are connected in series, a voltage of about 50 V to 100 V is required.

  The current command circuit 60 determines the magnitude of the current that flows through the light emitting element 3 and the duty ratio of the current that flows through the light emitting element 3. The current command circuit 60 in the present embodiment is configured by a general-purpose microcontroller (general-purpose microcomputer) 601. The general-purpose microcomputer 601 is, for example, an 8-bit microcomputer with a flash memory having an A / D conversion function. The general-purpose microcomputer 601 monitors the voltage at the voltage dividing point of the resistance elements 401 and 402 in the voltage detection circuit 40 based on the input from the 7th pin. As a result, the voltage across the light emitting element 3 corresponding to the voltage across the capacitor 202 is detected. The general-purpose microcomputer 601 determines whether or not to change the current of the light emitting element 3 based on the detected voltage. Furthermore, the general-purpose microcomputer 601 has a function of determining a lighting state and a function of detecting a load abnormality. For this reason, the 7th pin is set as an A / D conversion input. The second, third, and fourth pins are set to binary output. Pin 1 is a power supply terminal, and pin 8 is a ground terminal.

  The control circuit 50 controls the switching element 231 via the drive circuit 232 of the step-down chopper circuit 20 to supply the light emitting element 3 with desired power. As shown in FIG. 3, the control circuit 50 detects the value of the current flowing through the light emitting element 3 measured using the current detection resistor 301 in the current detection circuit 30. Then, the current value is adjusted using the error amplifier 501 in accordance with the detected current value. More specifically, the control signal input to the drive circuit 232 is generated by comparing the output voltage of the error amplifier 501 with the signal input to the negative terminal of the comparator 502. Thereby, the on / off operation of the switching element 231 in the step-down chopper circuit 20 is controlled, and the electric power supplied to the light emitting element 3 is adjusted. Note that the comparator 502 and the error amplifier 501 can be inexpensively configured with an IC or the like in which two operational amplifiers are incorporated in one package. The control voltage is the voltage Vcc.

  Hereinafter, an operation of generating a drive signal for the switching element 231 by the comparator 502 will be described with reference to FIG.

  FIG. 4 is a timing chart for explaining the operation of the control circuit 50 in the present embodiment. FIG. 4A shows the output voltage of the second pin of the general-purpose microcomputer 601. FIG. 4B shows the voltage of the capacitor 522 applied to the negative input terminal of the comparator 502. FIG. 4C shows the reference voltage applied to the positive input terminal of the comparator 502 (the broken line is the voltage of the capacitor 522). FIG. 4D shows the output terminal voltage of the comparator 502.

  When the output from the second pin of the general-purpose microcomputer 601 shown in FIG. 4A is at a high (H) level, the switching element 533 is in a conductive state (ON). At this time, the capacitor 522 is short-circuited, and the accumulated charge is discharged. Conversely, when the output from the second pin of the general-purpose microcomputer 601 is at a low (L) level, the switching element 533 is turned off (off). At this time, the capacitor 522 is charged via the resistance element 518, and the voltage gradually increases. The voltage of the capacitor 522 is applied to the negative input terminal of the comparator 502. Therefore, as shown in FIG. 4B, the value of the input signal at the negative input terminal of the comparator 502 is substantially zero when the switching element 522 is on, and gradually after the switching element 522 is turned off. To increase.

  The output voltage of the error amplifier 501 is applied to the positive input terminal of the comparator 502 as a reference voltage (solid line in FIG. 4C). As shown in FIG. 4D, the output of the comparator 502 is at the H level during the period when the voltage of the capacitor 522 (broken line in FIG. 4C) is lower than the reference voltage. On the contrary, in a period in which the voltage of the capacitor 522 is higher than the reference voltage, the output of the comparator 502 is L level. Therefore, on / off of the switching element 231 is driven at the same frequency as the signal output from the second pin of the general-purpose microcomputer 601. The pulse width of the output signal of the comparator 502 increases as the output voltage of the error amplifier 501 (solid line in FIG. 4C) increases. Therefore, the magnitude of the current flowing through the light emitting element 3 can be adjusted by changing the reference voltage of the positive input terminal of the error amplifier 501.

  Hereinafter, a method for changing the reference voltage input to the positive input terminal of the error amplifier 501 will be described. The switching element 531 is switched on / off at the frequency of the output signal of the 4th pin of the general-purpose microcomputer 601. By changing the on-time ratio of the switching element 531, the voltage value of the capacitor 523 can be adjusted. When the on-time ratio of the switching element 531 is less than a certain ratio, the capacitor 523 is charged, and a current flow of Vcc → resistance element 515 → capacitor 523 occurs. When the on-time ratio of the switching element 531 exceeds a certain ratio, a discharge occurs from the capacitor 523, and a current flow of the capacitor 523 → the resistance element 516 → the switching element 531 occurs. When the voltage value of the capacitor 523 is changed by changing the on-time ratio of the switching element 531, the reference voltage input to the positive input terminal of the error amplifier 501 changes. Thereby, by changing the ratio of the ON time of the switching element 531, the reference voltage of the positive input terminal of the error amplifier 501 can be changed, and the current of the light emitting element 3 can be adjusted.

  Control for causing a direct current to flow intermittently through the light emitting element 3 (referred to as PWM control) is realized by setting the on / off frequency and on-time ratio of the output of the third pin of the general-purpose microcomputer 601 to appropriate values. Is possible. The effective value of the current flowing through the light emitting element 3 can be controlled by switching on / off the output of the third pin at an arbitrary frequency and changing the ratio of the on time. The third pin of the general-purpose microcomputer 601 is connected to the gate of the switching element 532. By switching on / off the switching element 532, on / off of the current flowing through the light emitting element 3 can be controlled.

  Next, the configuration and operation of the dimming signal processing circuit 70 will be described.

  The dimming signal processing circuit 70 is a circuit that processes dimming signals transmitted from other devices. The dimming signal processing circuit 70 can be realized by, for example, a microcontroller (microcomputer) incorporating a memory for storing various programs and a CPU (Central Processing Unit). Such a microcomputer realizes functions to be described later by executing a program recorded in the memory by the CPU.

  The dimming signal processing circuit 70 receives the dimming signal Si sent from the outside, adjusts the signal level so that the dimming signal Si can be input to the general-purpose microcomputer 601, and inputs the signal to the fifth pin of the general-purpose microcomputer 601. The dimming signal Si is, for example, a 1 kHz PWM signal. The general-purpose microcomputer 601 detects the high voltage (Vh) and the low voltage (0 V) in the dimming signal Si, and determines lighting, extinction, and dimming ratio. The dimming signal processing circuit 70 changes at least one of the ON time timing (also referred to as “period timing”) and the period of the received dimming signal Si, and transmits the dimming signal So to the outside.

[Operation]
Next, a lighting operation by the light emitting element lighting device 1 according to the present embodiment will be described with reference to FIG.

  FIG. 5 is a timing chart showing temporal changes in the dimming signals Si and So and the current flowing through the light emitting element (sometimes referred to as “lighting current”) I in the present embodiment. FIG. 5 shows an example in which the dimming signal processing circuits 70 in the plurality of light emitting modules are connected to each other by conductive lines and dimming signals are sequentially transmitted. Here, the number of lighting devices 1 is n (n is an integer equal to or greater than 2), and the dimming signal received by the kth (k = 1, 2,..., N) lighting devices 1 is Sik and transmitted. The modulated light signal is Sok, and the current flowing through the light emitting element 3 is Ik. FIG. 5 shows, as an example, time changes of Si1, I1, So1, I2, So2, and I3. The dimming signal So1 and the dimming signal Si2 are the same, and the dimming signal So2 and the dimming signal Si3 are the same. Hereinafter, similarly, the dimming signal Sok and the dimming signal So (k + 1) are the same.

  In FIG. 5, the period of the dimming signal is T, and the dimming ratio is 50%. For example, when the frequency is 1 kHz, the period T is 1 ms. In the present embodiment, the circuit of the lighting device 1 is configured such that the waveform of the current Ik has a shape obtained by inverting the waveform of the dimming signal Sik. This is because when the dimming signal is not input (0 V or open), all lights are turned on.

  The dimming signal processing circuit 70 in the first light emitting element lighting device 1 adjusts the signal level of the received dimming signal Si1 and inputs it to the fifth pin of the general-purpose microcomputer 601. As a result, a lighting current I1 having a waveform obtained by inverting the waveform of the dimming signal Si1 flows through the light emitting element 3. The dimming signal processing circuit 70 determines the period and the dimming ratio during the period T after receiving the dimming signal Si1. Then, after the determination period T, a dimming signal So1 is transmitted with the cycle timing shifted by a half cycle (0.5T). That is, transmission is performed by shifting the on-time timing by an amount corresponding to a half cycle. The dimming signal So1 is received by the second lighting device 1.

  The dimming signal processing circuit 70 in the second light emitting element lighting device 1 adjusts the signal level of the received dimming signal Si2 (same as So1) and inputs it to the fifth pin of the general-purpose microcomputer 601. As a result, a lighting current I2 having a waveform obtained by inverting the waveform of the dimming signal Si2 flows through the light emitting element 3. The dimming signal processing circuit 70 determines the period and dimming ratio during the period T after receiving the dimming signal Si2. Then, after the determination period T, the dimming signal So2 is transmitted with the cycle timing shifted by a half cycle (0.5T). That is, transmission is performed with the on-time timing shifted by a half cycle. The dimming signal So2 is received by the third lighting device 1.

  The third and subsequent light-emitting element lighting devices 1 also operate in the same manner as described above.

  As described above, the dimming signal processing circuit 70 in the present embodiment changes the on-time timing of the dimming signal received from another dimming signal processing circuit by a time corresponding to half the cycle of the dimming signal. Then, it is sent to another dimming signal processing circuit. Thereby, the ratio with which the ON timing of the light emitting element in a some light emitting module overlaps can be reduced. For this reason, the ripple of a power supply current can be reduced and electromagnetic noise, acoustic noise, and heat generation can be reduced.

  In this embodiment, the on-time timing of the dimming signal is changed by a time corresponding to half of the period T, but the amount of change in the on-time timing may be set arbitrarily. By changing the on-time timing by a time shorter than the period T, it is effective because the ratio of overlapping the ON timing of the light emitting elements can be reduced.

  In the present embodiment, the period and the dimming ratio determination period are set to the period T, but the present invention is not limited to this. The determination period may be arbitrarily determined according to the detection and determination processing time. For example, the same effect can be obtained even if the determination period is set to an integral multiple of the period T.

(Embodiment 2)
Next, a second embodiment of the present disclosure will be described. The present embodiment is different from the first embodiment in that the amount of change in the on-time timing (or cycle timing) of the dimming signal is changed according to the dimming ratio. The basic configuration is the same as in the first embodiment. Hereinafter, description of the same points as in the first embodiment will be omitted, and only different points will be described.

  FIG. 6 is a diagram illustrating an example of the relationship between the dimming ratio and the change amount of the cycle timing in the present embodiment. In the illustrated example, the dimming signal processing circuit 70 changes the on-time timing of the received dimming signal by a half cycle (0.5 T) time when the dimming ratio is 50%. When the dimming ratio is different from 50%, the on-time timing is changed by an amount smaller than the amount corresponding to 0.5T determined according to the difference from 50%.

  FIG. 7 is a timing chart showing temporal changes in the light control signal and the current flowing through the light emitting element when the light control ratio is 70%. FIG. 7 shows time variations of Si1, I1, So1, I2, So2, and I3, as in FIG. In this example, since the light control ratio is 70%, the change amount of the cycle timing is set to 0.3T based on the relationship of FIG.

  FIG. 8 is a timing chart showing temporal changes in the light control signal and the current flowing through the light emitting element when the light control ratio is 30%. In this example, since the dimming ratio is 30%, the change amount of the cycle timing is set to 0.3T based on the relationship of FIG.

  In this manner, by changing the on-time timing according to the dimming ratio, it is possible to reduce the rate at which the ON timings of the light emitting elements in the plurality of light emitting modules overlap. For this reason, the ripple of a power supply current can be reduced and electromagnetic noise, acoustic noise, and heat generation can be reduced.

  In the present embodiment, the amount of change in the on-time timing varies in a linear function with respect to the dimming ratio for each of the dimming ratio in the range of 0 to 50% and the range of 50% to 100%. Without being limited to such an example, the relationship between the dimming ratio and the amount of change in the on-time timing of the dimming signal may be arbitrarily determined.

(Embodiment 3)
Next, a third embodiment of the present disclosure will be described. The present embodiment is different from the first embodiment in that the period is changed instead of the on-time timing of the dimming signal. The basic configuration is the same as in the first embodiment. Hereinafter, description of the same points as in the first embodiment will be omitted, and only different points will be described.

  FIG. 9 is a timing chart showing temporal changes in the light control signal and the current flowing through the light emitting element in the present embodiment. FIG. 9 shows time changes of Si1, I1, So1, I2, So2, and I3 as in FIG. In the present embodiment, the dimming signal processing circuit 70 in the first light emitting module changes the cycle of the received dimming signal Si1 from T to 0.5T and sends it out. The dimming signal processing circuit 70 in the second light emitting module changes the period of the received dimming signal Si2 (same as Sio) from 0.5T to T and sends it out. Hereinafter, similarly, the cycle of the dimming signal is switched between T and 0.5T. For example, when the frequency is 1 kHz, the period T is 1 ms, and 0.5T is 0.5 ms.

  In this way, the ratio of overlapping the ON timings of the light emitting elements in the plurality of light emitting modules can also be reduced by changing the cycle of the dimming signal. For this reason, the ripple of a power supply current can be reduced and electromagnetic noise, acoustic noise, and heat generation can be reduced.

  The dimming signal processing circuit 70 in the present embodiment switches the period between T and 0.5T, but the present disclosure is not limited to such an example. For example, the dimming signal processing circuit 70 in all the light emitting modules may set an arbitrary minimum cycle in advance and send out the received dimming signal while gradually shortening the cycle. However, it can be configured to return to the reference cycle when the minimum cycle is reached, and to repeat the same operation thereafter. Further, the period of the dimming signal may be changed so that a period having a preset period T0 and a period having an arbitrary period T1 shorter than the period T0 are repeated.

  You may perform both the process which changes the period in this embodiment, and the process which changes the period timing (on time timing) in Embodiment 1 or 2. FIG. By changing both the on-time timing and the cycle, it is possible to reduce the ratio of the ON timings of the light emitting elements in the plurality of light emitting modules overlapping.

(Embodiment 4)
Next, a fourth embodiment of the present disclosure will be described. The present embodiment relates to a light emitting module including a light emitting element lighting device and a light emitting element.

  FIG. 10 is a diagram illustrating the light emitting module of the present embodiment. This light-emitting module includes a light-emitting element 3, a light-emitting element lighting device 1, and a case for housing them. The light emitting element lighting device 1 is any one of the lighting devices according to the first to third embodiments. The light emitting element lighting device 1 includes a current control circuit 90 and a dimming signal processing circuit 70.

  FIG. 11 is a diagram illustrating an example of the appearance of the light emitting module. In this example, a circuit such as a DC / DC converter that constitutes the light-emitting element lighting device 1 is provided on the light-emitting element 3 that is an organic EL light-emitting panel, and these are covered by the back cover 4.

  The light emitting element 3 is an organic LED in which the input current and the light output are in a substantially proportional relationship, but may be an inorganic LED. A thin surface-emitting light source as shown in FIG. 11 is not limited to an organic LED, but can be realized by a light guide plate type inorganic LED.

  The light emitting module of this embodiment uses any one of the lighting devices 1 of the first to third embodiments. That is, it has a dimming signal processing circuit 70 that transmits at least one of the on-time timing and period of the received dimming signal. Accordingly, it is possible to reduce a ratio of overlapping timings of light emitting elements in a plurality of light emitting modules. As a result, ripples in the power supply current can be reduced, and electromagnetic noise, acoustic noise, and heat generation can be reduced.

(Embodiment 5)
Next, a fifth embodiment of the present disclosure will be described. The present embodiment relates to a lighting device including a plurality of light emitting modules.

  FIG. 12 is a block diagram illustrating a configuration of the illumination device according to the present embodiment. This illuminating device includes a power supply unit 110, a plurality of light emitting modules 120, and wiring connecting them. The power supply unit 110 is a device having the same function as the power supply circuit 2 in FIG. Each light emitting module 120 is the same as the light emitting module of the fourth embodiment.

The power supply unit 110 supplies power (voltage V _D ) to each light emitting module 120 and sends a dimming signal (S) to the first light emitting module. The dimming signal is transmitted to the next light emitting module with at least one of the on-time timing and the cycle changed by the dimming signal processing circuit 70 in each light emitting module.

  FIG. 13 is a perspective view showing an example of the appearance of the lighting device in the present embodiment. The lighting device 700 includes a light emitting unit 701 including a plurality of light emitting modules 120, a hanging tool 702 for installing the light emitting unit 701 on a ceiling, and a power cord 703 that connects the light emitting unit 701 and the hanging tool 702. The edge of the light emitting unit 701 is covered and protected by a lamp case 704. The hanging tool 702 has a remote control light receiving unit 705 for receiving a remote control signal transmitted from a remote control (not shown) on the surface thereof. The power supply unit 110 illustrated in FIG. 12 is provided, for example, inside the hanging tool 702 or on the back surface of the light emitting unit 701.

  The lighting device of this embodiment uses any one of the lighting devices 1 of the first to third embodiments. That is, it has a dimming signal processing circuit 70 that transmits at least one of the on-time timing and period of the received dimming signal. Accordingly, it is possible to reduce a ratio of overlapping timings of light emitting elements in a plurality of light emitting modules. As a result, ripples in the power supply current can be reduced, and electromagnetic noise, acoustic noise, and heat generation can be reduced.

  In addition, although the illuminating device 700 which concerns on this embodiment illustrated the structure suspended from a ceiling, the same effect can be acquired even if what is installed in a wall, the thing installed in the upper surface of a transparent case, etc.

(Embodiment 6)
Next, a light emitting element lighting device according to a sixth embodiment of the present disclosure will be described. The light emitting element lighting device of the present embodiment executes an operation for detecting an abnormality in addition to the operation performed by any one of the light emitting element lighting devices of the first to third embodiments. The configuration is the same as that in the first to third embodiments. Hereinafter, differences from the first to third embodiments will be described.

  The current control circuit 20 in the present embodiment is configured to operate by switching between a rated mode in which a rated current is passed through the light emitting element 3 and an abnormality detection mode in which a current smaller than the rated current is passed through the light emitting element 3. When the both-end voltage detected by the voltage detection circuit 40 in the abnormality detection mode is V0 and the both-end voltage detected by the voltage detection circuit 40 in the rated mode is V1, the difference (V1−V0) is greater than or equal to a predetermined threshold or 0 The output of current to the light emitting element 3 is stopped at the following times. By such an operation, it is possible to quickly detect a short circuit abnormality of the light emitting element 3 and stop power feeding. Hereinafter, this operation will be described in more detail.

[Lighting operation]
FIG. 14 is a flowchart showing the lighting operation of the light emitting element of this embodiment.

  FIG. 15 is a timing chart for explaining the rated current and the abnormality detection current in the present embodiment. FIG. 15A shows the change over time of the voltage Vin input to the light emitting element lighting device 1. FIG. 15B shows a change over time of the current Ila flowing through the light emitting element 3. FIG. 15C shows a change over time of the voltage Vla across the light emitting element 3. FIG. 15D shows the time change of the voltage difference (V1−V0).

  First, when the light emitting element lighting device 1 is powered on, the light emitting element lighting device 1 executes an initialization process (S11). As shown in FIG. 15A, when the input voltage Vin is applied from the power supply circuit 2 to the light emitting element lighting device 1, the power supply voltage Vcc is applied to the control circuit 50 and the current command circuit 60.

  Next, in response to an instruction from the current command circuit 60, the control circuit 50 causes the abnormality detection current I2 to flow through the light emitting element 3 (S12). In other words, the current command circuit 60 selects an abnormality detection mode (hereinafter sometimes simply referred to as “detection mode”) for a preset period t1 immediately after power-on. Here, the abnormality detection current I2 is a current for detecting an abnormality of the light emitting element 3 that is smaller than the rated current I1. The abnormality detection current I2 is supplied to the light emitting element 3 during the period t1. At this time, as shown in FIG. 15B, the value of the current Ila flowing through the light emitting element 3 is I2. Step S12 is a mode selection step of selecting a detection mode in which an abnormality detection current I2 for detecting an abnormality of the organic EL light emitting element is passed.

  While the abnormality detection current I2 flows through the light emitting element 3, the voltage detection circuit 40 performs measurement of the voltage Vla across the light emitting element 3 (S13). This both-ends voltage is acquired by measuring the voltage at the voltage dividing point between the resistance element 401 and the resistance element 402. The measurement result of this both-ends voltage is represented as V0. Step S13 is a voltage detection step of detecting the voltage V0 across the light emitting element 3. This measurement is continuously performed for a preset period t1 (S14).

  In step S14, when it is detected that the time during which the abnormality detection current I2 flows is longer than the set period t1 (Yes in S14), the control circuit 50 and the step-down chopper circuit 20 receive an instruction from the current command circuit 60, While the rated current I1 is passed through the light emitting element 3, the voltage detection circuit 40 measures the voltage Vla at both ends (S15). The measurement result of this both-ends voltage is represented as V1. Step S <b> 15 is a mode selection step of selecting a rated mode in which a rated current for turning on the light emitting element 3 flows.

  Here, the current command circuit 60 determines whether or not the difference (V1−V0) between the both-ends voltage Vla between the detection mode and the rated mode is greater than or equal to a threshold value ΔV set for abnormality detection, and less than zero. Is determined (S16). If the difference (V1−V0) between the both-ends voltage Vla is smaller than the threshold ΔV and is positive (Yes in S16), it is determined whether the light emitting element 3 is turned off (whether a turn-off signal is input) (S17). . If the turn-off signal is not received (No in S17), the process returns to the light emitting element steady lighting process in S15. When the turn-off signal is input (Yes in S17), the light emitting element 3 is turned off (S18). In step S16, if the difference (V1-V0) between both-ends voltage Vla is not less than the threshold value ΔV or not more than 0 (No in S16), the light emitting element 3 is turned off (S18).

  As described above, when the input voltage Vin is applied, the light-emitting element lighting device 1 in the present embodiment flows the abnormality detection current I2 to the light-emitting element 3 for a predetermined period t1 (detection mode). Thereafter, the rated current I1 is passed through the light emitting element 3 (rated mode). When the difference between the voltage V1 detected in the rated mode and the voltage V0 detected in the detection mode deviates from an appropriate range, it is determined that there is an abnormality and the current output to the light emitting element 3 is stopped. . Here, the period t1 can be set to, for example, 100 milliseconds or less so that the user does not feel the lighting delay.

  According to the light emitting element lighting device 1 and the light emitting element lighting method according to the present embodiment, the voltage V1 of the light emitting element detected when the abnormality detection current I2 smaller than the rated current I1 is passed and the voltage in the rated mode. Whether or not a short circuit abnormality has occurred is determined based on whether or not the difference from V0 is greater than or equal to a predetermined voltage value ΔV or less than or equal to 0. For this reason, the normal voltage value and the voltage value when the short-circuit abnormality occurs are clarified as compared with the case where the presence or absence of the short-circuit abnormality is determined based only on the voltage detected when the rated current I1 is passed. Can be determined. Therefore, according to the present embodiment, the short circuit abnormality can be detected with high accuracy, and the current output to the element having the short circuit abnormality can be reliably stopped. Furthermore, since a short circuit abnormality is detected at the time of starting, the non-light emission time can be suppressed.

  The current control circuit in the present embodiment executes the detection mode for a predetermined period immediately after power-on, but the detection mode may be performed in a period other than immediately after power-on. For example, the mode may be switched to the abnormality detection mode while the light emitting element 3 is continuously turned on in the rated mode. Further, the abnormality detection mode may be executed for a predetermined period immediately after the dimming signal is input from the dimming signal processing circuit 70. The rating mode and the abnormality detection mode may not be executed once, but alternately and continuously. By such an operation, it is possible to detect a short circuit abnormality at a timing other than immediately after power-on.

  In addition, you may use together with the method of determining a short circuit abnormality based on the voltage detected when the conventional rated current I1 is sent. By using the conventional method and the method of this embodiment together, it is possible to detect a short circuit abnormality with higher accuracy. For example, the voltage V0 may be detected and determined by transitioning to the abnormality detection mode triggered by the fact that the both-end voltage V1 in the rated mode has become a predetermined value lower than the rated voltage.

[Detection principle]
Here, it will be described that the light-emitting element lighting device and the light-emitting element lighting method according to the present embodiment described above have an advantageous effect as compared with the related art.

  FIG. 16 is a graph showing an example of voltage-current characteristics (resistance characteristics) of a normal light emitting element and a light emitting element in which a short circuit abnormality occurs. In this figure, solid lines (three lines) indicate voltage-current characteristics of a normal light emitting element. The voltage at which light emission of the light emitting element 3 starts (lighting start voltage) is V0. The rated voltage applied to the light emitting element 3 when the rated current I1 flows through the light emitting element 3 is V1. Here, the rated current means a constant current when the light-emitting element 3 is continuously lit as a light source of the lighting device (continuous light emission at the rated luminance).

  In FIG. 16, broken lines (three lines) indicate voltage-current characteristics of the light-emitting element 3 when a short circuit is abnormal. When the current is 0 A, the voltage is 0 V, indicating a substantially linear voltage-current characteristic.

  As shown in FIG. 16, the voltage-current characteristic of the light emitting element 3 having the short circuit abnormality has a large variation in the resistance value (the slope of the voltage with respect to the current) according to the short circuit state. For this reason, in the structure which determines abnormality of the light emitting element 3 based on the voltage value when the rated current I1 is flowing through the light emitting element 3, an erroneous determination may occur. When the rated current I1 is passed through the light emitting element 3, if the light emitting element 3 is normal, the voltage across it is the rated voltage V1. On the other hand, when a short circuit abnormality occurs in the light emitting element 3, the voltage across the both ends becomes smaller than the rated voltage V1. However, depending on the short-circuit state, the voltage between both ends may be close to the rated voltage V1, and thus the light emitting element 3 that should be determined to be abnormal may be erroneously determined to be normal.

  On the other hand, as the inspection current passed through the light emitting element 3 is reduced, the voltage value of the normal light emitting element 3 approaches the lighting start voltage V0, and the voltage value of the abnormal light emitting element 3 is less varied and becomes 0. Get closer. That is, as the abnormality detection current I2 is set smaller than the rated current I1, the difference between the voltage of the normal light emitting element 3 and the voltage of the abnormal light emitting element 3 increases. For this reason, a setting margin for the abnormality detection threshold voltage ΔV (= V1−V0) can be secured, and more accurate determination can be performed.

  From the above viewpoint, the abnormality detection current I2 may be set to be smaller than the rated current I1, but is preferably 10% to 1% or less of the rated current I1 in order to improve detection accuracy.

Hereinafter, each setting parameter in this embodiment is illustrated. For example, the rated voltage V1 of the light emitting element 3 is 7.5V, and the rated current I1 is 0.3A. At this time, the light emission area is 64 cm ² , the lighting start voltage V 0 is 5 V, the abnormality detection threshold voltage ΔV (= V 1 −V 0) is 3 V, and the abnormality detection current I 2 is 10 mA. The voltage at the time of normal abnormality detection current I2 is 5.5V.

  At this time, in the light emitting element 3 in which the short circuit abnormality has occurred, if the light emitting element voltage when the rated current I1 is passed is 5 V (resistance value is 16.7Ω (= 5 V / 0.3 A)), The light emitting element voltage when the current I2 is supplied is 0.17 V (= 16.7Ω × 10 mA). At this time, the voltage difference is 4.83 V (= 5 V−0.17 V), which is equal to or higher than the abnormality detection threshold voltage ΔV (3 V), and therefore it is possible to detect a short circuit abnormality. On the other hand, as shown in FIG. 15 (c), when an abnormality occurs during the rated lighting and the light emitting element voltage becomes 5V, the voltage difference becomes −0.5V (= 5V−5.5V) and becomes 0V or less. Abnormalities can be detected.

  The present embodiment is not limited to the above operation, and various modifications are possible. For example, the rated mode and the detection mode may be alternately executed, and the periods of the rated mode and the detection mode may be determined so that the light emitting element 3 emits light with a predetermined luminance. The time ratio between the rated mode and the detection mode can be set to a ratio such as 9: 1 or 99: 1. Such an operation may be performed not only immediately after power-on but also immediately after the dimming signal is input from the dimming signal processing circuit to the current control circuit. Or you may perform when the both-ends voltage V1 in rated mode becomes below a predetermined value lower than rated voltage. Hereinafter, an example of such an operation will be described.

  FIG. 17 is a flowchart showing an operation of repeating the rated mode and the detection mode when the voltage V1 across the light emitting element 3 in the rated mode becomes equal to or lower than a predetermined value V2 lower than the rated voltage.

  First, when the light emitting element lighting device is powered on, the light emitting element lighting device 1 executes an initialization process (S21).

  Next, the light emitting element lighting device 1 performs steady lighting processing (S22). That is, the control circuit 50 causes the rated current I1 to flow through the light emitting element 3 in response to an instruction from the current command circuit 60.

  Next, while the rated current I1 is flowing through the light emitting element 3, the voltage detection circuit 40 measures the voltage Vla across the light emitting element 3 (S23). This measured value is set to V1.

  Next, it is determined whether or not the light-emitting element 3 is turned off (whether a turn-off signal is input) (S24). If there is no turn-off signal, the process proceeds to step S25. When the turn-off signal is input (Yes in S24), the light emitting element 3 is turned off (S31).

  Next, it is compared whether the both-ends voltage V1 is larger than the predetermined voltage V2 smaller than the rated voltage (S25). When the both-end voltage V1 is equal to or lower than the voltage V2 (No in S25), the abnormality detection current I2 and the rated current I1 are alternately supplied to the light emitting element 3 (S26). That is, the detection mode and the rating mode are continuously switched. The abnormality detection current I2 and the rated current I1 flow to the light emitting element 3 during the period t2. When both-ends voltage V2 is larger than voltage V2 (Yes in S25), it returns to Step S23.

  Next, the voltage detection circuit 40 measures the voltage Vla across the light emitting element 3 when the abnormality detection current I2 flows through the light emitting element 3 (S27). This measured value is set to V2.

  Here, the current command circuit 60 determines whether or not the difference (V1−V0) between the both-ends voltage Vla between the detection mode and the rated mode is greater than or equal to a threshold value ΔV set for abnormality detection, and less than zero. Is determined (S28). If the difference (V1−V0) between the both-end voltages Vla is smaller than the threshold value ΔV and is positive (Yes in S28), after the elapse of the predetermined time t2 is confirmed in step S29, the light emitting element 3 is turned off (light-off signal). Is determined) (S30). If there is no turn-off signal (No in S30), the process returns to the steady lighting process in step S22. When the turn-off signal is input (Yes in S30), the light emitting element 3 is turned off (S31). In step S28, if the difference (V1-V0) between both-ends voltage Vla is not less than the threshold value ΔV or not more than 0 (No in S28), the light emitting element 3 is turned off (S31). Here, the period t2 may be about several hundred milliseconds, for example.

  According to this lighting method, it is possible to suppress the non-light emission time, detect a short circuit abnormality state of the light emitting element 3 more accurately during lighting, and stop the light emitting element current.

  Note that the operation of the sixth embodiment is established independently of the operations of the first to third embodiments. For this reason, in the sixth embodiment, the dimming signal processing circuit 70 may not be provided. Moreover, a light emitting module (corresponding to Embodiment 4) including the light emitting element lighting device 1 of Embodiment 6 and a light emitting device including a plurality of such light emitting modules (corresponding to Embodiment 5) can be constructed.

  The light emitting element lighting device of the present disclosure can be used for an illumination device including a plurality of light emitting modules.

DESCRIPTION OF SYMBOLS 1 Light emitting element lighting device 2 Power supply circuit 3 Light emitting element 10 Control power supply circuit 20 Buck chopper circuit 30 Current detection circuit 40 Voltage detection circuit 50 Control circuit 60 Current command circuit 70 Dimming signal processing circuit 90 Current control circuit 110 Power supply unit 120 Light emitting module 101, 102, 401, 402, 515, 516, 518 Resistance element 113 Zener diode 201 Electrolytic capacitor 202, 522, 523 Capacitor 211 Regenerative diode 221 Inductor 231, 531, 532, 533 Switching element 301 Current detection resistor 501 Error amplifier 502 Comparator 601 General-purpose microcomputer 700 Illuminating device 701 Light emitting unit 702 Hanging tool 703 Power cord 704 Lamp case 705 Remote control light receiving unit

Claims (19)

A light-emitting element lighting device that is mounted on each light-emitting module in a lighting device including a plurality of light-emitting modules and lights a light-emitting element,
A current control circuit which is connected to the light emitting element and modulates a current flowing through the light emitting element based on an input dimming signal;
An input interface and an output interface; receiving the dimming signal via the input interface; inputting the dimming signal to the current control circuit; and changing a cycle of the dimming signal to output the output A dimming signal processing circuit for sending out from the interface;
With
The dimming signal processing circuit changes the cycle of the dimming signal received from the dimming signal processing circuit in the other light emitting module, and further sends it to the dimming signal processing circuit in the other light emitting module.
Light emitting element lighting device.   The dimming signal processing circuit changes the on-time timing of the dimming signal received from the dimming signal processing circuit in the other light emitting module, and further sends it to the dimming signal processing circuit in the other light emitting module. The light emitting element lighting device according to claim 1.   3. The light emitting element lighting device according to claim 2, wherein the dimming signal processing circuit changes the on-time timing of the received dimming signal by changing it for a time shorter than the cycle of the dimming signal.   The light-emitting element lighting device according to claim 3, wherein the dimming signal processing circuit changes the on-time timing of the received dimming signal by changing the time corresponding to half the period of the dimming signal.   The light-emitting element lighting device according to claim 2, wherein the dimming signal processing circuit changes the on-time timing of the received dimming signal by changing the time according to the dimming ratio.   When the dimming ratio is 50%, the dimming signal processing circuit changes the on-time timing of the received dimming signal by a time corresponding to half the period of the dimming signal, and the dimming ratio is 50%. 6. The light emitting element lighting device according to claim 5, wherein the on-time timing is changed by a time shorter than a time corresponding to half of the period determined according to a difference from 50%.   The light-emitting element lighting device according to claim 1, wherein the dimming signal processing circuit transmits the received dimming signal with a shorter cycle.   The dimming signal processing circuit receives the dimming signal so that a period having a preset period T0 and a period having a period T1 shorter than the period T0 are repeated. The light-emitting element lighting device according to claim 1, wherein the light-emitting element lighting device is sent while changing a cycle. A voltage detection circuit for detecting a voltage across the light emitting element;
The current control circuit is configured to operate by switching between a rated mode for flowing a rated current to the light emitting element and an abnormality detection mode for flowing a current smaller than the rated current to the light emitting element. When the voltage between both ends detected by the voltage detection circuit is V0 and the voltage between both ends detected by the voltage detection circuit in the rated mode is V1, the difference (V1-V0) is greater than or equal to a predetermined threshold value or less than 0. The light-emitting element lighting device according to claim 1, wherein output of current to the light-emitting element is stopped.   The light emitting element lighting device according to claim 9, wherein the current control circuit switches to the abnormality detection mode while the light emitting element is continuously lit in the rated mode.   The light emitting element lighting device according to claim 9 or 10, wherein the current control circuit executes the abnormality detection mode for a predetermined period immediately after power-on.   The light emitting element lighting device according to claim 9, wherein the current control circuit executes the abnormality detection mode for a predetermined period immediately after the dimming signal is input from the dimming signal processing circuit. .   The light emitting element lighting device according to claim 9, wherein the current control circuit alternately executes the rated mode and the abnormality detection mode.   The current control circuit executes the rated mode and the abnormality detection mode alternately immediately after turning on the power, and each period of the rated mode and the abnormality detection mode so that the light emitting element emits light with a predetermined luminance. The light emitting element lighting device according to claim 13, wherein:   The current control circuit alternately executes the rated mode and the abnormality detection mode immediately after the dimming signal is input from the dimming signal processing circuit so that the light emitting element emits light with a predetermined luminance. The light emitting element lighting device according to claim 13 or 14, wherein each period of the rated mode and the abnormality detection mode is determined. The light emitting device according to any one of claims 9 to 15, wherein the current control circuit switches to the abnormality detection mode when the both-end voltage V1 in the rated mode becomes equal to or lower than a predetermined value lower than the rated voltage. Lighting device. The current control circuit executes the rated mode and the abnormality detection mode alternately when the both-ends voltage V1 in the rated mode becomes a predetermined value lower than the rated voltage. The light emitting element lighting device in any one. A light-emitting element lighting device according to any one of claims 1 to 17,
A light emitting element connected to the light emitting element lighting device and lit by the light emitting element lighting device;
A light emitting module comprising:   A lighting device comprising a plurality of light emitting modules, each of which is the light emitting module according to claim 18.

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