JP2014204110A - Led drive and illuminating device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED drive which allows for recognition of the necessity of maintenance work while protecting normal LEDs, and to provide an illuminating device including the same.SOLUTION: When at least one of the voltage V to be applied to an LED module 10 including an LED, currents Ia, Ib supplied to the LED units 10a, 10b of the LED module 10 including an LED, and the temperature of the LED units 10a, 10b of the LED module 10 including an LED does not fall in a predetermined range, an LED drive 1 for driving a plurality of LEDs by constant current control limits current supply to the LED unit of the LED module 10 including that LED, and supplies the currents Ia, Ib to the LED unit of the LED module 10 including the LED by protective operation A and protective operation B of a predetermined control mode.

Description

  The present invention relates to an LED driving device and a lighting device including the same.

  2. Description of the Related Art In recent years, illumination devices using high-luminance LEDs as a light source for illumination are known. An LED unit in which a plurality of LEDs are connected in series is connected in parallel and driven by an LED driving device. In such an illuminating device, an illuminating device including an LED driving device (LED driving circuit) that cuts off the current supply to the LED unit when an abnormality of the LED such as a short circuit or an open LED occurs is known. For example, as in Patent Document 1.

JP 2009-252344 A

  However, the LED driving device described in Patent Document 1 blocks the current to the LED unit in which an abnormality has occurred in the LED, but does not notify the user that an abnormality has occurred in the LED. For this reason, an LED unit including an LED in which an abnormality has occurred over a long period of time without performing maintenance work may be used.

  This invention is made in view of the subject which concerns, and while providing a normal LED, it can provide the LED drive device which can recognize the necessity of a maintenance work, and an illuminating device provided with the same. Objective.

  That is, the LED driving device disclosed in the present application is an LED driving device that drives a plurality of LEDs by constant current control, and at least one of a voltage applied to the LED, a current supplied to the LED, and a temperature of the LED is When it is not within the predetermined range, the supply of current to the LED is reduced and the current is supplied to the LED in a predetermined control mode.

  The LED driving device disclosed in the present application further includes notification means for notifying the outside in a predetermined manner when the notification means starts supplying the current in the predetermined control manner.

  The illumination device disclosed in the present application includes the above-described LED driving device.

  As effects of the present invention, the following effects can be obtained.

  According to the luminaire disclosed in the present application, an excessive current supply is suppressed by detecting a failure of the LED. Thereby, while protecting normal LED, the presence or absence of the necessity for maintenance work can be recognized.

1 is a schematic configuration diagram of a lighting device according to the present invention. The block diagram of the illuminating device which concerns on 1st embodiment of this invention. The figure which shows the flowchart showing the control aspect of the illuminating device which concerns on 1st embodiment of this invention. The block diagram of the illuminating device which concerns on 2nd embodiment of this invention. The figure which shows the flowchart showing the control aspect of the illuminating device which concerns on 2nd embodiment of this invention. The block diagram of the illuminating device which concerns on 3rd embodiment of this invention. The block diagram of the illuminating device which concerns on 4th embodiment of this invention. The block diagram of the illuminating device which concerns on 5th embodiment of this invention. The block diagram of the illuminating device which concerns on 6th, 7th, 8th embodiment of this invention. The side view of the lighting fixture which comprises the illuminating device of this invention. Sectional drawing of the lighting fixture which comprises the illuminating device of this invention. The irradiation surface side top view of the lighting fixture which comprises the illuminating device of this invention.

  First, the illuminating device 101 which detects the abnormal voltage which is 1st embodiment of the illuminating device which concerns on this invention using FIG. 1 and FIG. 2 is demonstrated.

[1. LED abnormality detection operation (1)]
As shown in FIG. 1, the illuminating device 101 is an illuminating device 101 which uses LED as a light source. The illumination device 101 includes the LED driving device 1, the LED module 10, the dimming control device 11, and the like. The illuminating device 101 is configured by connecting an LED module 10 and a dimming control device 11 to the LED driving device 1.

  As shown in FIG. 2, the LED driving device 1 supplies a current I to the LED module 10. The LED driving device 1 includes a DC / DC converter 2, resistors Ra and Rb and a control circuit 3.

  The resistors Ra and Rb are used to set currents Ia and Ib flowing in the LED units 10a and 10b constituting the LED module 10. One side of resistance Ra * Rb is comprised so that it may be connected to LED unit 10a * 10b comprised in parallel, respectively. The other sides of the resistors Ra and Rb are grounded via a resistor R0 and connected to the DC / DC converter 2. That is, the currents Ia and Ib flowing through the LED units 10a and 10b can be determined by setting the resistance values of the resistors Ra and Rb to arbitrary values. The resistors R1 and R2 are used to convert the currents Ia and Ib into the voltages Va and Vb.

  The DC / DC converter 2 outputs the current I in a predetermined control mode. The DC / DC converter 2 is connected to the DC power supply Vcc at the input terminal. Here, the DC power supply Vcc refers to an AC / DC converter (not shown) that converts an AC current from an AC commercial power supply into a DC current. The DC / DC converter 2 is configured to convert the direct current supplied from the input terminal into an arbitrary current value, and to output the converted direct current from the output terminal. The DC / DC converter 2 is configured to be able to control the current I to be output based on a PWM dimming signal Sc and an error signal Se from a control circuit 3 described later.

  The DC / DC converter 2 is configured such that a voltage V, which is the sum of the voltage Va and the voltage Vb applied to cause the currents Ia and Ib to flow through the resistors Ra and Rb, can be acquired as the feedback signal Sf. The DC / DC converter 2 is configured to be able to maintain the current I output based on the feedback signal Sf at a predetermined value. That is, the DC / DC converter 2 supplies the current I to the LED module 10 by constant current control.

  The control circuit 3 controls the DC / DC converter 2. The control circuit 3 is composed of a microcomputer, for example. The control circuit 3 includes a dimming table storage unit 4, a threshold voltage storage unit 5, a PWM signal generation unit 6, an error signal generation unit 7, a voltage detection unit 8, and a calculation unit 9.

  The dimming table storage unit 4 stores dimming rate information Sa. The dimming table storage unit 4 includes a part of a storage area of a memory (for example, a flash memory or an EEPROM) in the control circuit 3 unit. The dimming table storage unit 4 stores in advance dimming rate information Sa, which is information related to the dimming rate of the LED module 10 set for each dimming instruction signal Sad from the dimming control device 11. The dimming table storage unit 4 is configured to transmit the dimming rate information Sa to the calculation unit 9.

  The threshold voltage storage unit 5 stores threshold voltage information Ss. The threshold voltage information Ss is information regarding the threshold voltage for determining whether or not an abnormality has occurred in the LED module 10. The threshold voltage storage unit 5 includes a part of the storage area of the memory in the control circuit 3. The threshold voltage storage unit 5 stores in advance threshold voltage information Ss corresponding to each dimming rate information Sa. Specifically, the threshold voltage information Ss is set for each dimming stage based on the voltage V applied to the LED module 10 when the LED module 10 is driven at each dimming stage. Thereby, the control circuit 3 can detect the abnormality of LED reliably at an early stage. The threshold voltage information Ss can also be set based on the voltage V applied to the LED module 10 when the LED module 10 is driven at the maximum dimming stage. The threshold voltage storage unit 5 is configured to be able to transmit the threshold voltage information Ss to the calculation unit 9.

  Further, the threshold voltage information Ss may be calculated according to the characteristics of the LED module 10. Specifically, when the power is turned on, the lighting device 101 supplies current from the LED driving device 1 to the LED module 10 based on the dimming rate information Sa. At this time, the control circuit 3 of the LED drive device 1 acquires the voltage V applied to the LED module 10 or the LED units 10a and 10b. The calculation unit 9 of the control circuit 3 is configured to be able to calculate threshold voltage information Ss for each dimming stage from the voltage Vb of the dimming stage stored in advance as a design value and the acquired voltage V. Thereby, it is possible to prevent malfunction due to variations in the characteristics of the LEDs.

  The PWM signal generation unit 6 generates the PWM dimming signal Sc based on the PWM signal generation information Sp from the calculation unit 9. The PWM signal generation unit 6 is configured to be able to transmit the generated PWM dimming signal Sc to the DC / DC converter 2.

  The error signal generation unit 7 generates an error signal Se based on the error determination signal Sj from the calculation unit 9. The error signal Se is a signal that causes the DC / DC converter 2 to stop outputting the current I. The error signal generator 7 is configured to be able to transmit the generated error signal Se to the DC / DC converter 2.

  The voltage detector 8 detects the voltage V applied to the LED module 10. The voltage detection unit 8 is configured in parallel with the LED module 10 connected to the LED driving device 1. Specifically, the voltage detection unit 8 is connected to the anode side and the cathode side of the LED units 10 a and 10 b in the LED module 10. The voltage detector 8 detects the voltage V applied to the LED module 10 at regular time intervals. The voltage detector 8 is configured to convert the detected voltage V into a digital signal Vd and transmit it to the calculator 9. Note that the voltage detection unit 8 may be configured to transmit the detected digital signal Vd of the voltage V to the calculation unit 9 as needed, or may be configured to transmit the digital signal Vd to the calculation unit 9 in response to a request from the calculation unit 9. The voltage detection unit 8 may be configured to transmit an analog signal to the calculation unit 9 instead of the digital signal Vd.

  The calculation unit 9 calculates the value of the current I supplied to the LED module 10. The calculation unit 9 is configured to be able to calculate the coordinate data D based on the dimming instruction signal Sad from the dimming control device 11. The coordinate data D represents a position on the data for obtaining the dimming rate information Sa and the threshold voltage information Ss corresponding to the dimming instruction signal Sad from the dimming table storage unit 4 and the threshold voltage storage unit 5. It is a thing. The calculation unit 9 is configured to be able to acquire dimming rate information Sa from the dimming table storage unit 4 using the coordinate data D. The calculation unit 9 is configured to be able to generate the PWM signal generation information Sp based on the acquired dimming rate information Sa. The PWM signal raw hide information Sp is, for example, a digital signal.

  Moreover, the calculating part 9 determines the state of the LED module 10. The calculation unit 9 is configured to be able to acquire the digital signal Vd of the voltage V from the voltage detection unit 8 at regular intervals. The calculation unit 9 is configured to be able to acquire the threshold voltage information Ss from the threshold voltage storage unit 5 using the coordinate data D. The calculation unit 9 can make an error determination by comparing the acquired digital signal Vd with the threshold voltage information Ss. The calculation unit 9 is configured to be able to generate an error determination signal Sj based on error determination. The error determination signal Sj is, for example, a digital signal. In addition, it is desirable to set the above-mentioned fixed time to a short time in order to quickly determine the abnormality of the LED.

  The calculation unit 9 is connected to the dimming table storage unit 4 and can acquire dimming rate information Sa stored in the dimming table storage unit 4.

  The calculation unit 9 is connected to the threshold voltage storage unit 5 and can acquire threshold voltage information Ss stored in the threshold voltage storage unit 5.

  The calculation unit 9 is connected to the PWM signal generation unit 6 and can transmit the PWM signal generation information Sp to the PWM signal generation unit 6.

  The calculation unit 9 is connected to the error signal generation unit 7 and can transmit the error determination signal Sj to the error signal generation unit 7.

  The calculation unit 9 is connected to the voltage detection unit 8 and can acquire the digital signal Vd of the voltage applied to the LED module 10 detected by the voltage detection unit 8.

  The calculation unit 9 is connected to the dimming control device 11 and can acquire the dimming instruction signal Sad from the dimming control device 11.

  The PWM signal generation unit 6 is connected to the DC / DC converter 2 and can transmit the PWM dimming signal Sc to the DC / DC converter 2.

  The PWM signal generator 6 is connected to the DC / DC converter 2 and can transmit the error signal Se to the DC / DC converter 2.

  The LED module 10 is a light source configured by connecting a plurality of LEDs. The LED module 10 is configured by connecting in parallel LED units 10a and 10b in which one or more LEDs are connected in series. In the LED module 10, the LED units 10 a and 10 b may be mounted on the same substrate, or may be mounted on different substrates. Moreover, in this embodiment, although the LED module 10 is comprised from LED unit 10a and LED unit 10b, it is not limited to this, What is necessary is just to be comprised from one or more LED units.

  The LED module 10 is connected to the LED driving device 1. Specifically, the anode side terminals of the LED units 10 a and 10 b constituting the LED module 10 are connected to the output terminal of the DC / DC converter 2. Further, the cathode side terminals of the LED units 10a and 10b are connected to the resistors Ra and Rb, respectively. Thereby, the LED module 10 determines the electric current Ia * Ib which flows into LED unit 10a * 10b based on resistance value of resistance Ra * Rb.

  The dimming control device 11 instructs the LED driving device 1 to perform dimming. The dimming control device 11 is connected to the LED driving device 1. The dimming control bag is configured to transmit a dimming instruction signal Sad to the control circuit 3 of the LED driving device 1. That is, the illumination device 101 is configured such that the user can change the brightness and color tone of the LED module 10 via the dimming control device 11. In the present embodiment, the connection mode between the LED driving device 1 and the dimming control device 11 may be wired or wireless such as infrared communication. For example, the light adjustment control device 11 and the LED driving device 1 may be provided with a light projecting unit and a light receiving unit, respectively, and may be configured by a remote controller that performs infrared communication between them.

  Below, the control aspect of the LED drive device 1 of the illuminating device 101 which concerns on 1st embodiment of this invention is demonstrated using FIG. 2 and FIG.

  The LED drive device 1 of the illumination device 101 acquires the dimming instruction signal Sad from the dimming control device 11 in the calculation unit 9 of the control circuit 3. The calculation unit 9 acquires the dimming rate information Sa from the dimming table storage unit 4 based on the acquired dimming instruction signal Sad. The calculation unit 9 generates the PWM signal generation information Sp and transmits it to the PWM signal generation unit 6.

  The PWM signal generation unit 6 generates the PWM dimming signal Sc based on the acquired PWM signal generation information Sp. The PWM signal generation unit 6 transmits the generated PWM dimming signal Sc to the DC / DC converter 2. The DC / DC converter 2 supplies the current I to the LED module 10 based on the acquired PWM dimming signal Sc.

  The current I supplied from the DC / DC converter 2 is supplied to the LED module 10. The current I is shunted to the currents Ia and Ib at a shunt ratio determined by the resistance values of the resistors Ra and Rb. Currents Ia and Ib flow in the LED units 10a and 10b of the LED module 10, respectively. In the LED units 10a and 10b, when the currents Ia and Ib are supplied, the respective LEDs are lit with a luminance corresponding to the current Ia or the current Ib.

  The DC / DC converter 2 acquires, as a feedback signal Sf, a voltage V that is the sum of the voltage Va and the voltage Vb applied to cause the currents Ia and Ib to flow through the resistors Ra and Rb. The DC / DC converter 2 controls the current I output based on the acquired feedback signal Sf to a constant current value.

  When the digital signal Vd acquired from the voltage detection unit 8 is not included in the range of the threshold voltage information Ss acquired from the threshold voltage storage unit 5, the calculation unit 9 determines that a failure has occurred in the LED and performs a predetermined protection operation. I do. When an open failure occurs in at least one LED included in the LED module 10, the voltage applied to the LED module 10 is the current Ia or Ib that flows through the LED unit 10a or the LED unit 10b in which no LED open failure has occurred. It rises by increasing. Further, when a short-circuit failure occurs in at least one LED included in the LED module 10, the voltage applied to the LED module 10 is caused by the balance between the current Ia and the current Ib flowing through the LED units 10a and 10b being lost. descend.

  Accordingly, when the digital signal Vd is larger than the upper limit value of the threshold voltage information Ss, the calculation unit 9 determines that an LED open failure has occurred and performs a predetermined protection operation A. In addition, when the digital signal Vd is smaller than the lower limit value of the threshold voltage information Ss, the calculation unit 9 determines that an LED short-circuit failure has occurred and performs a predetermined protection operation B. When the digital signal Vd is within the threshold voltage information Ss, the calculation unit 9 determines that no failure has occurred in the LED.

  Next, the control mode of the control circuit 3 of the LED driving device 1 will be specifically described with reference to FIG.

As shown in FIG. 3, in step S <b> 110, the calculation unit 9 of the control circuit 3 determines whether or not the dimming instruction signal Sad is acquired from the dimming control device 11.
As a result, when it is determined that the dimming instruction signal Sad has been acquired from the dimming control device 11, the calculation unit 9 shifts the step to step S120.
On the other hand, when it is determined that the dimming instruction signal Sad has not been acquired from the dimming control device 11, the arithmetic unit 9 shifts the step to step S150.

  In step S120, the calculation unit 9 calculates the coordinate data D based on the acquired dimming instruction signal Sad, and moves the step to step S130.

  In step S130, the calculation unit 9 acquires the dimming rate information Sa from the dimming table storage unit 4 based on the coordinate data D, and shifts the step to step S140.

  In step S140, the calculation unit 9 acquires threshold voltage information Ss from the threshold voltage storage unit 5 based on the coordinate data D, and shifts the step to step S150.

  In step S150, the calculating part 9 acquires the digital signal Vd which converted the voltage value detected from the voltage detection part 8, and makes a step transfer to step S160.

In step S160, the arithmetic unit 9 determines whether or not the acquired digital signal Vd is within the range of the threshold voltage information Ss.
As a result, when it is determined that the acquired digital signal Vd is within the range of the threshold voltage information Ss, the arithmetic unit 9 shifts the step to step S170.
On the other hand, when it is determined that the acquired digital signal Vd is not within the range of the threshold voltage information Ss, the calculation unit 9 shifts the step to step S270.

  In step S170, the calculating part 9 produces | generates the PWM signal generation information Sp from the acquired light control rate information Sa, and makes a step transfer to step S180.

  In step S180, the calculation unit 9 transmits the generated PWM signal generation information Sp to the PWM signal generation unit 6, and returns the step to step S110.

In step S270, the arithmetic unit 9 determines whether or not the acquired digital signal Vd is larger than the upper limit value of the threshold voltage information Ss.
As a result, when it is determined that the acquired digital signal Vd is larger than the upper limit value of the threshold voltage information Ss, the arithmetic unit 9 shifts the step to step S280.
On the other hand, when it is determined that the acquired digital signal Vd is not larger than the upper limit value of the threshold voltage information Ss, that is, when it is determined that the acquired digital signal Vd is smaller than the lower limit value of the threshold voltage information Ss, the calculation unit 9 Shifts the step to step S380.

  In step S280, the calculation unit 9 performs a predetermined protection operation A assuming that an LED open failure has occurred, and ends the control.

  In step S380, the calculation unit 9 performs a predetermined protection operation B assuming that a short circuit failure of the LED has occurred, and ends the control.

  By configuring in this way, the lighting device 101 according to the first embodiment performs a short circuit failure and an open failure of the LED by comparing the threshold voltage information Ss by the control circuit 3 of the LED driving device 1 and the detected voltage V. It is configured to be distinguishable. Furthermore, the lighting device 101 can appropriately perform the protection operation A and the protection operation B, which are control modes corresponding to the failure mode, by the control circuit 3. Details of the protection operation A and the protection operation B will be described later.

[2. LED abnormal current detection operation (2)]
Next, with reference to FIG. 4, a lighting device 102 that detects an abnormal current, which is a second embodiment of the lighting device according to the present invention, will be described. In the following embodiments, the same points as those of the above-described embodiments will not be specifically described, and different portions will be mainly described.

  As shown in FIG. 4, the control circuit 3 of the LED driving device 1 controls the DC / DC converter 2. The control circuit 3 includes a current detection unit 12 in addition to the dimming table storage unit 4, the threshold voltage storage unit 5, the PWM signal generation unit 6, the error signal generation unit 7, and the calculation unit 9.

  The current detection unit 12 detects currents Ia and Ib flowing through the LED units 10 a and 10 b of the LED module 10. The current detection unit 12 is connected to the cathode sides of the LED units 10a and 10b via diodes D1 and D2, respectively. The current detector 12 detects currents Ia and Ib flowing through the LED units 10a and 10b at regular intervals. The current detection unit 12 is configured to convert the detected currents Ia and Ib into voltage digital signals Vda and Vdb and transmit them to the calculation unit 9. The current detection unit 12 may be configured to transmit the digital signals Vda and Vdb to the calculation unit 9 as needed, or may be configured to transmit the digital signal Vda / Vdb to the calculation unit 9 in response to a request from the calculation unit 9. The current detection unit 12 may be configured to transmit an analog signal to the calculation unit 9 instead of the digital signals Vda and Vdb.

  The calculating part 9 determines the state of the LED module 10. The calculating part 9 is comprised so that digital signal Vda * Vdb can be acquired from the electric current detection part 12 for every fixed time. The calculation unit 9 is configured to be able to acquire the threshold voltage information Ss from the threshold voltage storage unit 5 using the coordinate data D. The calculation unit 9 is configured to be able to transmit the error determination signal Sj to the error signal generation unit 7 by comparing the acquired digital signal Vda / Vdb with a threshold voltage based on the threshold voltage information Ss. The error determination signal Sj is, for example, a digital signal.

  The calculation unit 9 is connected to the current detection unit 12, and can acquire digital signals Vda and Vdb of voltages obtained by converting the currents Ia and Ib flowing in the LED units 10a and 10b detected by the current detection unit 12, respectively. .

  Below, the control aspect of the LED drive device 1 of the illuminating device 102 which concerns on 2nd embodiment of this invention is demonstrated using FIG. 4 and FIG.

  As shown in FIG. 4, when the digital signal Vda / Vdb acquired from the current detection unit 12 is not included in the range of the threshold voltage information Ss acquired from the threshold voltage storage unit 5, the calculation unit 9 causes a failure in the LED. It is determined that a predetermined protection operation (protection operation A or protection operation B) is performed.

  The current I supplied to the LED module 10 is subjected to constant current control by the DC / DC converter 2 and has a constant current value. When an open failure of at least one LED included in the LED module 10 occurs, no current flows through the LED unit including the LED in which the open failure has occurred. As a result, the constant current control by the DC / DC converter 2 increases the current flowing through the LED unit in which no LED open failure has occurred. In addition, when a short circuit failure of at least one LED included in the LED module 10 occurs, a voltage drop due to the LED is reduced, thereby increasing a current flowing through the LED unit including the LED in which the short circuit failure has occurred. As a result, the constant current control by the DC / DC converter 2 reduces the current flowing through the LED unit in which no LED short-circuit failure has occurred.

  Therefore, when at least one of the digital signals Vda and Vdb is 0V, the arithmetic unit 9 determines that an open failure has occurred in the LED and performs a predetermined protection operation A. Further, when at least one of the digital signals Vda and Vdb is smaller than the lower limit value of the threshold voltage information Ss, the arithmetic unit 9 determines that a short circuit failure has occurred in the LED and performs a predetermined protection operation B.

  Next, the control mode of the control circuit 3 of the LED driving device 1 will be specifically described with reference to FIG.

  As shown in FIG. 5, in steps S110 to S140, the calculation unit 9 of the control circuit 3 calculates the coordinate data D based on the dimming instruction signal Sad from the dimming control device 11, and the dimming rate information Sa, When the threshold voltage information Ss is acquired, the step proceeds to step S150.

  In step S150, the calculating part 9 acquires the digital signal Vda * Vdb which converted the voltage calculated | required from electric current Ia * Ib detected from the electric current detection part 12, and makes a step transfer to step S160.

In step S460, the arithmetic unit 9 determines whether or not the acquired digital signals Vda and Vdb are within the range of the threshold voltage information Ss.
As a result, when it is determined that the acquired digital signals Vda and Vdb are within the range of the threshold voltage information Ss, the arithmetic unit 9 shifts the step to step S170.
On the other hand, when it is determined that the acquired digital signal Vd is not within the range of the threshold voltage information Ss, the arithmetic unit 9 shifts the step to step S570.

  In step S170 to step S180, the calculation unit 9 transmits the PWM signal generation information Sp generated from the dimming rate information Sa to the PWM signal generation unit 6, and returns the step to step S110.

In step S570, the arithmetic unit 9 determines whether at least one of the acquired digital signals Vda and Vdb is 0V.
As a result, when it is determined that at least one of the acquired digital signals Vda and Vdb is 0 V, the arithmetic unit 9 shifts the step to step S580.
On the other hand, when it is determined that the acquired digital signals Vda and Vdb are not 0 V, the arithmetic unit 9 shifts the step to step S680.

  In step S580, the calculation unit 9 performs a predetermined protection operation A assuming that an LED open failure has occurred, and ends the control.

  In step S680, the calculation unit 9 performs a predetermined protection operation B assuming that a short circuit failure of the LED has occurred, and ends the control.

  With this configuration, the illumination device 102 according to the second embodiment is based on the comparison between the threshold voltage information Ss by the control circuit 3 of the LED driving device 1 and the detected currents Ia · Ib (digital signals Vda · Vdb). The LED is configured to be able to distinguish between a short circuit failure and an open failure. Furthermore, the lighting device 102 can appropriately perform the protection operation A and the protection operation B, which are control modes corresponding to the failure mode, by the control circuit 3 of the LED driving device 1. Details of the protection operation A and the protection operation B will be described later.

[3. LED abnormality detection operation (3)]
Next, a lighting device 103 that detects an abnormal current, which is a third embodiment of the lighting device according to the present invention, will be described with reference to FIG.

  As shown in FIG. 6, the control circuit 3 of the LED driving device 1 controls the DC / DC converter 2. The control circuit 3 includes polyswitches 13a and 13b in addition to the dimming table storage unit 4, the threshold voltage storage unit 5, the PWM signal generation unit 6, the error signal generation unit 7, the voltage detection unit 8, and the calculation unit 9. doing.

  The polyswitches 13a and 13b are for minimizing the current that flows due to a change in resistance value with temperature. The polyswitches 13a and 13b are thermistors having a positive temperature coefficient. When the polyswitches 13a and 13b are heated by overcurrent and the temperature of the polyswitches 13a and 13b rises, the resistance value increases significantly. The poly switches 13a and 13b are respectively provided on circuits to which the LED units 10a and 10b of the LED module 10 are connected. As a result, currents Ia and Ib flowing in the LED units 10a and 10b flow in the poly switches 13a and 13b.

  When an open failure of at least one of the LEDs included in the LED module 10 occurs, the current flowing through the LED unit in which the open failure of the LED does not occur is increased by constant current control by the DC / DC converter 2. In other words, the polyswitch connected to the LED unit in which the LED open failure has not occurred increases in temperature and increases in resistance value. Thereby, the voltage applied to the LED module 10 rises.

  On the other hand, when a short circuit failure of at least one of the LEDs included in the LED module 10 occurs, the voltage drop due to the LED decreases. That is, the current flowing through the LED unit including the LED in which the short circuit failure has occurred increases. As a result, the voltage applied to the LED module 10 temporarily decreases, but the temperature of the polyswitch connected to the LED unit in which the short-circuit failure has occurred rises and the resistance value increases, whereby the LED module 10 The voltage applied to rises again.

[4. (Protection operation)
When the digital signal Vd is larger than the upper limit value of the threshold voltage information Ss, the calculation unit 9 determines that an open failure or a short-circuit failure has occurred in the LED and performs a predetermined protection operation A. A thermal fuse may be provided in place of the polyswitches 13a and 13b. With this configuration, the lighting device 103 can appropriately perform the protection operation A, which is a control mode corresponding to the failure mode, by the control circuit 3 of the LED driving device 1. In the present embodiment, the protection operation B is the same as the protection operation A.

  Hereinafter, the protection operation A and the protection operation B will be described in detail. The following protection operation A and protection operation B are combinations of predetermined protection operations with the illumination devices 101, 102, and 103, the illumination devices 102a and 102b, and the illumination devices 101c, 102c, and 103c, which are embodiments of the present invention. Is possible.

  The protection operation A is a predetermined protection operation when an open failure of the LED occurs. In this case, the voltage applied to the LED module 10 increases, and the current flowing through the LED unit in which no LED open failure has occurred is greater than the current based on the dimming rate information Sa. The protection operation B is a predetermined protection operation when a short circuit failure of the LED occurs. In this case, the voltage applied to the LED module 10 decreases, and the current flowing through the LED unit in which the LED short-circuit failure has occurred is greater than the current based on the dimming rate information Sa.

[4-1. (Power-down operation)
First, a power-down operation for reducing the output of the DC / DC converter 2 will be described as a first embodiment of the protection operation.

  In the protection operation A, the calculation unit 9 of the control circuit 3 is supplied to the LED module 10 so that the current flowing in the LED unit in which no open failure has occurred is equal to the current based on the dimming rate information Sa. PWM signal generation information Sp for reducing the current I is generated. Then, the calculation unit 9 transmits the generated PWM signal generation information Sp to the PWM signal generation unit 6. The PWM signal generator 6 generates a PWM dimming signal Sc based on the PWM signal generation information Sp and transmits it to the DC / DC converter 2. That is, the control circuit 3 performs a power-down operation for reducing the output of the current I of the DC / DC converter 2 (hereinafter simply referred to as “power-down operation”). Thereby, the current I supplied from the DC / DC converter 2 to the LED module 10 decreases. Note that the output of the current I of the DC / DC converter 2 may be reduced to a predetermined value.

  In the protection operation B, the calculation unit 9 of the control circuit 3 performs the power-down operation so that the current flowing through the LED unit in which the short circuit failure has occurred is equal to or less than the current value based on the dimming rate information Sa. Thereby, the current I supplied from the DC / DC converter 2 to the LED module 10 decreases. In the calculation unit 9 of the lighting device 101, the current I after the power-down operation is set based on the voltage drop state of the LED module 10. Note that the control circuit 3 may be capable of performing an operation of uniformly reducing the output of the current I of the DC / DC converter 2 to a predetermined value.

  By performing the power-down operation, the lighting devices 101, 102, and 103 prevent the failure of other LEDs while ensuring the functions of the lighting devices 101, 102, and 103 even if an LED open failure occurs. be able to. In addition, the lighting devices 101, 102, and 103 can prevent other LEDs from failing while ensuring the minimum necessary functions as the lighting devices 101, 102, and 103 even if a short circuit failure occurs in the LEDs. .

[4-2. (Blinking operation)
Next, a blinking operation will be described as a second embodiment of the protection operation. This embodiment is configured such that the LED module 10 blinks at a predetermined interval in addition to the power-down operation according to the first embodiment described above. In another embodiment, a buzzer may be provided as a notification unit.

  In the protection operation A and the protection operation B, the calculation unit 9 of the control circuit 3 generates PWM signal generation information Sp that can execute a power-down operation and an operation in which the LED module 10 blinks at a predetermined interval. Then, the calculation unit 9 transmits the generated PWM signal generation information Sp to the PWM signal generation unit 6. The PWM signal generator 6 generates a PWM dimming signal Sc based on the PWM signal generation information Sp and transmits it to the DC / DC converter 2. That is, the control circuit 3 performs a power-down operation for suppressing the output of the current I of the DC / DC converter 2 and also performs a blinking operation. When a buzzer is further provided, a notification operation by the buzzer may be performed in addition to the blinking operation.

  By performing the blinking operation, the lighting devices 101, 102, and 103 can notify the user that an LED open failure or a short-circuit failure has occurred, so that the user recognizes the notification and the lighting devices 101, 102 -If the power supply of 103 is turned off, failure of other LEDs can be prevented. Moreover, failure of other LED can be prevented by performing power-down operation | movement with alerting | reporting operation | movement.

[4-3. (Self disconnection operation)
Next, a self-breaking operation will be described as a third embodiment of the protection operation with reference to FIG. This embodiment is applied to the lighting device 102a which is the fourth embodiment of the lighting device in which the temperature fuses 14a and 14b are further provided in the lighting device 102 which is the second embodiment of the lighting device. In the lighting device 102a, thermal fuses 14a and 14b are respectively provided in circuits to which the LED units 10a and 10b are connected. The thermal fuses 14a and 14b include a disconnection heater. The calculation unit 9 is connected to each disconnection heater, and can control the disconnection heater.

  In the protection operation A, the arithmetic unit 9 performs a power down operation. Thereby, the current I supplied from the DC / DC converter 2 to the LED module 10 decreases.

  In the protection operation B, the arithmetic unit 9 operates the heater for disconnecting the thermal fuse of the LED unit in which the short circuit failure has occurred. The calculation unit 9 determines that the temperature fuse has broken because the voltage V applied to the LED module 10 is not increased or the current flowing through the LED unit cannot be detected. That is, the control circuit 3 performs a self-breaking operation in which the thermal fuse of the LED unit in which the short circuit failure has occurred is disconnected by the disconnection heater. As a result, the constant current control by the DC / DC converter 2 increases the current flowing through the LED unit in which no short circuit failure has occurred.

  The calculation unit 9 performs the power-down operation together. Thereby, the current I supplied from the DC / DC converter 2 to the LED module 10 decreases.

  By performing the self-breaking operation, the lighting device 102a can prevent the failure of other LEDs while ensuring the function as the lighting device 102a even if the open failure or short circuit failure of the LED occurs.

  Further, as another embodiment of the self-breaking operation, a configuration in which a thermal fuse is provided in a circuit to which the LED module 10 is connected may be used. In the protection operation A / B, when an open failure or a short-circuit failure occurs, the arithmetic unit 9 operates the heater for disconnecting the thermal fuse to perform a self-breaking operation. Thereby, the current I is not supplied from the DC / DC converter 2 to the LED module 10.

  By performing the self-breaking operation, the lighting device 102a can prevent an increase in the number of failure points due to continued use after an open failure or short circuit failure of the LED.

[4-4. (Output stop operation)
Next, an output stop operation will be described as a fourth embodiment of the protection operation. In the present embodiment, since the same protection operation is performed in the protection operation A and the protection operation B, only the protection operation A will be described.

  In the protection operation A, the calculation unit 9 transmits an error determination signal Sj to the error signal generation unit 7. The error signal generator 7 generates an error signal Se based on the error determination signal Sj from the calculator 9. The error signal generator 7 transmits the generated error signal Se to the DC / DC converter 2. That is, the control circuit 3 performs an output stop operation for stopping the output of the current I of the DC / DC converter 2 (hereinafter simply referred to as “output stop operation”). Thereby, the current I supplied from the DC / DC converter 2 to the LED module 10 stops. The output stop operation may be canceled by a predetermined release operation or the like.

  By performing the output stop operation, the lighting devices 101, 102, and 103 can prevent the failure of other LEDs due to the occurrence of an open failure or short-circuit failure of the LED.

[4-5. (Thinning lighting operation)
Next, a thinning lighting operation will be described as a fifth embodiment of the protection operation. In the present embodiment, since the same protection operation is performed in the protection operation A and the protection operation B, only the protection operation A will be described. The present embodiment is the same as the second embodiment of the lighting device provided with the switch elements 15a and 15b, or the first embodiment of the lighting device including the plurality of LED driving devices 1. The present invention is applied to the lighting devices 101, 102, and 103 that are the third embodiment.

  As shown in FIG. 8, in the lighting device 102b, switch elements 15a and 15b are provided in circuits to which the LED units 10a and 10b are connected, respectively. The calculation unit 9 of the control circuit 3 is connected to the switch elements 15a and 15b, and can control the switch elements 15a and 15b, respectively. As the switch elements 15a and 15b, bipolar transistors, field effect transistors (MOS-FETs), and the like can be employed.

  In the protection operation A, the arithmetic unit 9 turns off the switch elements 15a and 15b connected to the LED unit including the LED in which the open failure or the short-circuit failure has occurred. As a result, only the LED unit in which no open failure or short-circuit failure has occurred is lit, and the current flowing through the LED unit is increased by the constant current control of the DC / DC converter 2. That is, the control circuit 3 performs the thinning-out lighting operation by turning off the switch element of the LED in which the open failure or the short-circuit failure has occurred.

  The calculation unit 9 performs the power-down operation together. Thereby, the current I supplied from the DC / DC converter 2 to the LED module 10 decreases.

  Moreover, in the illuminating devices 101, 102, and 103 including the plurality of LED driving devices 1, the supply of the current I to the LED module 10 including the LED in which the open failure or the short-circuit failure has occurred is stopped. Specifically, in the protection operation A, the calculation unit 9 of the LED drive device 1 driving the LED module 10 in which an open failure or a short-circuit failure has occurred performs a stop operation. Thereby, the supply of the current I from the DC / DC converter 2 to the LED module 10 is stopped. In other words, the lighting devices 101, 102, and 103 perform the thinning lighting operation by stopping the supply of the current I to the LED module 10 including the LED in which the open failure or the short-circuit failure has occurred.

  By performing the thinning-out lighting operation, the lighting devices 101, 102, and 103 can prevent other LEDs from failing while ensuring the functions of the lighting devices 101, 102, and 103 even if an LED open failure or short circuit failure occurs. Can be prevented.

[4-6. (Light source switching operation)
Next, switching operation to another light source will be described as a sixth embodiment of the protection operation. In the present embodiment, since the same protection operation is performed in the protection operation A and the protection operation B, only the protection operation A will be described.

  As shown in FIG. 9, in the present embodiment, the lighting device 101, 102, and 103 that are the third embodiment of the lighting device are further provided with a sub LED drive device 16, a sub LED module 17, and a control device 18. The present invention is applied to the lighting devices 101c, 102c, and 103c that are the sixth, seventh, and eighth embodiments of the provided lighting device. In the illumination devices 101c, 102c, and 103c, the LED drive device 1 and the sub LED drive device 16 are connected to the control device 18, respectively. Note that “sub LED drive device 16” has “sub” added to the configuration name, which means that the device is independent of the LED drive device 1, and the LED drive device It is not meant to be an auxiliary role. The “sub LED module 17” has the same meaning.

  The control device 18 controls the LED driving device 1 and the sub LED driving device 16. The control device 18 is composed of, for example, a microcomputer. The control device 18 is configured to be able to calculate the coordinate data D based on the dimming instruction signal Sad from the dimming control device 11. The control device 18 is configured to be able to acquire the result of error determination performed by the calculation unit 9 of the control circuit 3 in the LED driving device 1.

  The control device 18 is connected to the dimming control device 11 and can obtain the dimming instruction signal Sad from the dimming control device 11.

  The control device 18 is connected to the control circuit 3 of the LED drive device 1, and can transmit the calculated coordinate data D to the control circuit 3 of the LED drive device 1. Further, the control device 18 is configured to be able to acquire the result of error determination performed by the control circuit 3 of the LED driving device 1.

  The control device 18 is connected to the control circuit 3 of the sub LED drive device 16, and can transmit the calculated coordinate data D to the control circuit 3 of the sub LED drive device 16.

  When the control device 18 determines that an open failure or a short-circuit failure has occurred from the result of the error determination obtained from the control circuit 3 of the LED drive device 1, the control device 18 transmits a stop signal to the control circuit 3 of the LED drive device 1. On the other hand, the control device 18 transmits predetermined coordinate data D to the control circuit 3 of the sub LED driving device 16.

  In the protection operation A, the calculation unit 9 of the LED drive device 1 performs an output stop operation. Note that the current I may be intermittently supplied by decreasing the output of the current I of the DC / DC converter 2. Further, the output stop operation may be canceled by a predetermined release operation or the like.

  The calculation unit 9 of the sub LED drive device 16 generates the PWM signal generation information Sp based on the coordinate data D. Then, the calculation unit 9 transmits the generated PWM signal generation information Sp to the PWM signal generation unit 6. The PWM signal generator 6 generates a PWM dimming signal Sc based on the PWM signal generation information Sp and transmits it to the DC / DC converter 2. Thereby, the control circuit 3 supplies the current Is from the DC / DC converter 2 of the sub LED driving device 16 to the sub LED module 17. That is, the lighting devices 101c, 102c, and 103c perform the switching operation of stopping the supply of the current I to the LED module 10 in which the open failure or the short-circuit failure has occurred and supplying the current Is to the sub LED module 17.

  By performing the switching operation, the lighting devices 101c, 102c, and 103c can prevent other LEDs from failing while ensuring the functions of the lighting devices 101c, 102c, and 103c even if an LED open failure or short circuit failure occurs. Can be prevented.

[4-7. (Recovery action)
Next, a recovery operation will be described as a seventh embodiment of the protection operation. In the present embodiment, since the same protection operation is performed in the protection operation A and the protection operation B, only the protection operation A will be described. This embodiment is applied to the lighting device 103 which is the third embodiment (see FIG. 6) of the lighting device provided with the poly switches 13a and 13b.

  As shown in FIG. 6, in the protection operation A, the arithmetic unit 9 performs an output stop operation. Thereby, the current I supplied from the DC / DC converter 2 to the LED module 10 is stopped. The resistance values of the poly switches 13a and 13b connected to the LED units 10a and 10b of the LED module 10 decrease as the temperature decreases due to natural heat dissipation.

  The calculation unit 9 transmits the PWM signal generation information Sp generated after a predetermined time has elapsed to the PWM signal generation unit 6. The PWM signal generation unit 6 generates the PWM dimming signal Sc based on the PWM signal generation information Sp acquired from the calculation unit 9. The PWM signal generation unit 6 transmits the generated PWM dimming signal Sc to the DC / DC converter 2. Since the resistance value of the poly switches 13a and 13b decreases with a decrease in temperature due to natural heat dissipation, a current flows through the LED units 10a and 10b, and the LEDs are turned on. That is, the control circuit 3 performs a recovery operation for supplying the current I to the LED module 10 again.

By performing the recovery operation, the lighting device 103 can prevent the failure of other LEDs while ensuring the function as the lighting device 103 even when an open failure or short-circuit failure of the LED occurs.
Note that the notification means may be provided in the illumination device 103 or in the LED driving device 1.

[5. (Configuration of lighting equipment)
Here, the lighting fixture 200 which is one embodiment of the lighting fixture including the lighting device 101 according to the present invention will be described with reference to FIGS. 10 to 12.

  The lighting fixture 200 according to the present embodiment is a lighting fixture that uses the LED module 10 driven by the LED driving device 1 as a main light source. The lighting fixture 200 is a ceiling light that is directly attached to a mounting surface such as a ceiling. In the following description, the side that irradiates light will be described as the irradiation surface side of the lighting fixture 200, and the side that is attached to an attachment surface such as a ceiling will be described as the attachment surface side.

  As illustrated in FIGS. 10 and 11, the lighting fixture 200 mainly includes a fixture main body 201, an LED driving device 1 that is a power supply device, an LED module 10 that is a light source unit, and a shade 207.

  The appliance main body 201 constitutes the main body of the lighting fixture 200. The lighting fixture 200 according to this embodiment has a circular planar shape, and the outer contour shape of the fixture main body 201 in a plan view is also circular. The instrument main body 201 mainly includes a housing portion 202, an attachment hole 203, a substrate attachment portion 204, a first protection member attachment portion 205, and a second protection member attachment portion 206. The instrument body 201 is formed of a metal plate such as aluminum having thermal conductivity. In the present embodiment, the board attachment portion 204, the first protection member attachment portion 205, the second protection member attachment portion 206, and the like are formed by sheet metal processing.

  The accommodating part 202 is provided in the center part of the instrument main body 201 in the radial direction. The accommodating part 202 is a part in which the LED drive device 1 which is a power supply device for lighting the LED module 10 which is a light source part, a lighting device (not shown), etc. are accommodated. The accommodating part 202 is covered with the accommodating part cover 208, and the height and width | variety for accommodating the LED drive device 1, a lighting device, etc. are ensured inside.

  The attachment hole 203 is a part to which an adapter (not shown) is attached when the lighting apparatus 200 is attached to the ceiling. The attachment hole 203 is provided at a position that is the center of the instrument body 201 in the radial direction. The attachment hole 203 is provided so as to penetrate from the lower surface side of the housing portion 202 to the upper surface side of the instrument main body 201. When the lighting fixture 200 is attached to the ceiling, for example, the adapter is attached to the ceiling wiring fixture (hanging ceiling) for the lighting fixture, and the adapter is attached so as to be inserted into the mounting hole 203.

  The board attaching part 204 is a part to which the LED module 10 that is a light source part is attached. The board attachment portion 204 is formed so as to protrude toward the irradiation surface side of the instrument main body 201. The surface on which the LED module 10 is arranged is formed flat. The region in which the board attaching portion 204 is formed is a region surrounding the accommodating portion 202, is radially outside the instrument main body 201 relative to the accommodating portion 202, and is closer to the instrument main body 201 than the outer peripheral edge portion of the instrument main body 201. This is a region slightly inside in the radial direction.

  The LED driving device 1 and the lighting device are accommodated in the accommodating portion 202. The LED driving device 1 is provided with a connector 1a. When attaching the lighting fixture 200 to a ceiling, for example, the connector 1a is electrically connected to an external power source through a ceiling wiring fixture for the lighting fixture by connecting the connector 1a to a connector (not shown) on the adapter side. The lighting device and the LED module 10 are electrically connected by an electric wire (not shown).

  The seed 207 is attached to the irradiation surface side of the instrument main body 201. The shade 207 covers the irradiation surface side of the instrument body 201. The shade 207 is a member that distributes light to the outside while reflecting and diffusing light from the LED module 10. The seed 207 is formed of a resin material having translucency. The overall shape of the shade 207 is circular in plan, and gently swells in a dome shape on the irradiation surface side. The shade 207 has a structure that can be attached to and detached from the instrument main body 201 for cleaning the inside of the shade 207, replacing parts of the instrument main body 201, and the like.

  As shown in FIG. 12, the LED module 10 has a plurality of LED units 10a, 10b,. In the present embodiment, the LED module 10 includes eight LED units 10a, 10b, 10c, 10d, 10e, 10f, 10g, and 10h corresponding to the board mounting portion 204. Each LED unit 10a, 10b,... Is configured by mounting a plurality of LED elements 209 on a substrate. The LED module 10 is disposed on the board mounting portion 204. The plurality of LED units 10 a, 10 b,... Are arranged in an annular shape having a certain width in the radial direction of the instrument body 201 in a state where the LED units 10 a, 10 b,.

  The lighting fixture 200 configured as described above can turn on an LED with an arbitrary luminance based on a dimming instruction from the dimming control device 11 using the above-described lighting device 101 or the like. In addition, the lighting apparatus 200 allows the user to determine whether or not there is a failure of the LED when the lighting device 101 performs the protective operation A and the protective operation B for the LED module 10 when an LED open failure or short circuit failure occurs. It is possible to notify.

As described above, in the LED driving device 1 for driving a plurality of LEDs according to the present invention by constant current control, the voltage V applied to the LED module 10 including the LEDs, and the LED of the LED module 10 including the LEDs. If at least one of the currents Ia and Ib supplied to the units 10a and 10b and the temperature of the LED unit 10a and 10b of the LED module 10 including the LED is not within a predetermined range, the LED of the LED module 10 including the LED The current supply to the unit is restricted, and the currents Ia and Ib are supplied to the LED unit of the LED module 10 including the LEDs in the protection operation A and the protection operation B which are predetermined control modes.
By comprising in this way, abnormality of LED can be detected and normal LED can be protected.

In addition, the LED driving device 1 and the lighting devices 101, 102, and 103 including the LED driving device 1, when the supply of current according to a predetermined control mode is started, the notification unit is in a predetermined mode, such as a buzzer, blinking operation, and thinning lighting Further, a notification means for notifying the outside by the operation, the switching operation, and the recovery operation is further provided.
By comprising in this way, the LED drive device 1 which can recognize the necessity of a maintenance operation | work, and the illuminating device 101 * 102 * 103 provided with it can be provided.
In the present embodiment, a ceiling light is used as an example of a lighting fixture. However, the present invention is useful if the lighting fixture includes at least a plurality of LED units.

DESCRIPTION OF SYMBOLS 1 LED drive device 10 LED module 10a LED unit 10b LED unit Ia Current Ib Current A Protection operation B Protection operation 101 Lighting device 102 Lighting device 103 Lighting device

Claims (3)

An LED driving device for driving a plurality of LEDs with constant current control,
When at least one of the voltage applied to the LED, the current supplied to the LED, and the temperature of the LED is not within the predetermined range, the amount of current supplied to the LED is reduced and the current is supplied to the LED in a predetermined control mode. LED drive device to supply. The LED driving device according to claim 1,
An LED driving device further comprising a notifying means for notifying the outside in a predetermined manner when the supply of current in the predetermined control manner is started.   A lighting device comprising the LED driving device according to claim 1.

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