JP2012204255A - Led lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lighting device capable of preventing an erroneous determination of an LED abnormality when the LED is in an intermittent lighting state.SOLUTION: An LED lighting device comprises an LED light source part 19; a continuous power circuit 14; and a battery 21 charged by the continuous power circuit 14. An LED lighting circuit supplies a direct current power from the battery to the LED light source part, and lights the LED. A lighting control part switches a lighting state of the LED in the LED light source part between a continuous lighting and an intermittent lighting. An LED abnormality detection part detects an LED abnormality in the LED light source part. An abnormality detection control part changes the abnormality detection control of the LED abnormality detection part to the continuous lighting state and the intermittent lighting state of the LED in the LED light source part.

Description

  Embodiments described herein relate generally to an LED lighting device that lights an LED using an external power source or a battery power source.

  For example, there are guide lights and emergency lights as illuminating devices for performing guidance display of evacuation passages and the like, and those using LEDs as light sources have been adopted. LEDs that illuminate the display surface of emergency lights and guide lights are always supplied with power from the commercial power source, and are always supplied with power from the commercial power source due to a power failure from the commercial power source. In the event of an emergency, the LED is turned on with power from the battery. In addition, since the required brightness is legally determined in the guide light, when the LED has an abnormality and the brightness is reduced, the LED is informed of the abnormality and normally the LED is turned off.

  On the other hand, there are LEDs that intermittently light up the display surface of the guide light in the event of an emergency such as a power failure or fire. (For example, refer to Patent Document 1) Here, in the following description, intermittent lighting is not only blinking lighting that repeatedly turns on and off, but also light lighting and dark lighting, lighting and dark lighting, and lighting and dark lighting are repeated. Including bright and dark lighting.

  As a guide light lighting device, when a short circuit abnormality occurs in a light source (LED) in the event of an emergency such as a power failure or disaster, the light source (LED) that does not have an abnormality is turned on and the role as a guide light is given top priority. There is what was made to do (for example, refer to patent documents 2). In this guide lamp lighting device, when a short circuit abnormality of the LED constituting the lamp occurs during normal use, the power supply to the constant current circuit is stopped to give priority to the protection of the constant current circuit, and the LED constituting the lamp is short-circuited in an emergency. When an abnormality occurs, the power supply to the constant current circuit is continued to serve as a guide light rather than protecting the constant current circuit. Further, when an open abnormality of the LED constituting the lamp occurs during normal use and emergency, power supply to the constant current circuit of the lamp is stopped to reduce power consumption.

JP 2009-187845 A JP 2006-286339 A

  However, if LED abnormality detection such as LED short-circuit abnormality or LED open abnormality is performed under the same conditions of continuous lighting and intermittent lighting of LED, the lighting state is different, so that the LED is not abnormal particularly during intermittent lighting. However, it may be erroneously determined as abnormal. When an abnormality of the LED is detected, the LED is turned off and turned off in principle, and therefore, for example, a guide light or an emergency light may turn off due to an erroneous determination.

  Embodiment of this invention is providing the LED lighting device which can prevent the erroneous determination of LED abnormality when LED is a state of intermittent lighting.

  The LED lighting device of the embodiment of the present invention includes an LED light source unit; a constant power circuit; and a battery charged by the constant power circuit. Furthermore, the LED lighting circuit supplies DC power from the battery to the LED light source unit to light the LED. The lighting control unit switches the lighting state of the LED of the LED light source unit between continuous lighting and intermittent lighting. The LED abnormality detection unit detects an abnormality of the LED of the LED light source unit. The abnormality detection control unit varies the abnormality detection control of the LED abnormality detection unit between continuous lighting and intermittent lighting of the LED of the LED light source unit.

  According to the embodiment of the present invention, erroneous determination of LED abnormality can be prevented when the LED is intermittently lit.

The block diagram of the LED lighting device which concerns on embodiment of this invention. Explanatory drawing of an example at the time of determining the short circuit failure of LED of the LED light source part in the LED abnormality detection part of the stable circuit in embodiment of this invention.

  Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram of an LED lighting device according to an embodiment of the present invention. The alternating current from the commercial power supply 11 is input to the rectifier circuit 12 and converted to direct current. The direct current obtained by the rectifier circuit 12 is input to the power supply monitoring circuit 13, smoothed by the smoothing capacitor C <b> 1, and always input to the power supply circuit 14. The constant power supply circuit 14 steps down the DC voltage obtained by the rectifier circuit 12 to obtain a normal power supply, and supplies the normal power supply to the charging circuit 15 via the transformer Tr1, the diode D1, and the smoothing capacitor C2. Further, the regular power supply is supplied to the LED lighting circuit 16 through the transformer Tr1, the diode D2, and the smoothing capacitor C3.

  The charging circuit 15 always stores an emergency power source in the battery 21 with a normal power source obtained via the transformer Tr1, the diode D1, and the smoothing capacitor C2 of the power source circuit 14 at all times when power is supplied from the commercial power source 11. .

  In addition, the constant LED lighting circuit 16 is a normal power source obtained through the transformer Tr1, the diode D2, and the smoothing capacitor C3 of the constant power supply circuit 14 when the power is supplied from the commercial power supply 11, and is lit through the diode D3. A lighting current is supplied to the LED light source unit 19 via the control circuit 22. The LED light source unit 19 is configured by connecting a plurality of LEDs 30 in series.

  That is, the constant LED lighting circuit 16 inputs the lighting current of the LED 30 of the LED light source unit 19 via the lighting control circuit 22 at any time when power is supplied from the commercial power supply 11, and determines a predetermined LED light source unit. The current is controlled so as to be 19 constant load currents. The power supply circuit 18 of the constant power supply circuit 14 feeds back the lighting current supplied from the constant LED lighting circuit 16 to the LED 30 of the LED light source unit 19 as a load via the constant current feedback circuit 20, and supplies the current to the LED 30 of the LED light source unit 19. Controls the lighting current to be supplied.

  Next, the emergency power supply circuit 25 is activated in the event of an emergency when the commercial power supply 11 becomes a power failure, boosts the DC voltage from the battery 21, and turns on the emergency power supply for lighting the LEDs 30 of the LED light source unit 19. The LED light source unit 19 is supplied via 22. At the same time, power is supplied to the microcomputer 23. That is, the emergency power supply circuit 25 inputs a lighting current to the LED 30 of the LED light source unit 19 in an emergency when the commercial power supply 11 is interrupted, and the emergency load current of the LED light source unit 19 is determined in advance. The current is controlled so that

  Further, the emergency power circuit 25 continuously lights the LEDs 30 of the LED light source unit 19 with the power from the battery 21 for a time determined by law, and then turns on the LEDs 30 intermittently. This is to reduce the power consumption of the LED so that the lighting time of the LED 30 of the LED light source unit 19 can be lengthened even when the commercial power supply fails.

  The power supply monitoring circuit 13 detects that the commercial power supply 11 has failed. When the power supply monitoring circuit 13 detects that the commercial power supply 11 has failed, it notifies the microcomputer 23 accordingly. The microcomputer 23 activates the IC 26 of the emergency power supply circuit 25 when receiving a notification that the commercial power supply 11 has failed. When the IC 26 is activated, the switch element 27 is turned on / off to boost the output voltage of the battery 21 so that the lighting current of the LED 30 of the LED light source unit 19 becomes an emergency lighting current. Emergency power is supplied to the lighting control circuit 22 via the transformer Tr2, the diode D4, and the smoothing capacitor C4. Then, after a lapse of time stipulated by law, an emergency power supply for intermittently lighting the LED 30 is supplied to the LED 30 of the LED light source unit 19. At the same time, power is also supplied to the microcomputer 23 via the transformer Tr2, the diode D5, and the smoothing capacitor C5.

  As described above, the power from the power supply circuit 14 is always input to the microcomputer 23 via the charging circuit 15 as a power supply, and the power from the emergency power supply circuit 25 is supplied to the power supply in an emergency. Is entered as

  Next, the safety circuit 35 includes an LED abnormality detection unit 17 that monitors the voltage of a predetermined number of LEDs 30 connected in series to the LED light source unit 19 and detects an abnormality of the LED 30.

  FIG. 2 is an explanatory diagram of an example when determining a short-circuit failure of the LED 30 of the LED light source unit 19 in the LED abnormality detection unit 17 of the stabilization circuit 35. As shown in FIG. 2, the LED abnormality detection part 17 detects a voltage for every three LED30 connected in series, and monitors the voltage. The short circuit failure signal of the LED 30 from the LED abnormality detection unit 17 of the safety circuit 35 is input to the microcomputer 23. When the microcomputer 23 inputs the short circuit failure signal of the LED 30, the power supply to the LED light source unit 19 is performed. Stop. In FIG. 2, the voltage is detected for each of the three LEDs 30 as the predetermined number, but the number is not limited to three, and one may be two, or even four or more. Furthermore, it is good also as all the numbers which comprise the LED light source part 19. FIG.

  Next, LED abnormality detection control in the LED abnormality detection unit 17 will be described. The LED abnormality detection unit 17 determines whether or not the voltage of the predetermined number of LEDs 30 is equal to or higher than a predetermined normal threshold at all times when power is supplied from the commercial power supply 11. And when it is more than a normal threshold value, it judges that LED30 is normal, and when the voltage of the predetermined number of LED30 of the LED light source part 19 is less than a normal threshold value, it is a short circuit failure of LED30 of the LED light source part 19. judge.

  In the event of an emergency when the commercial power supply is interrupted, the LED 30 of the LED light source unit 19 is continuously lit so as to have a predetermined emergency load current before the time stipulated by law. Therefore, it is determined whether the voltage of the predetermined number of LEDs 30 is equal to or higher than a predetermined emergency threshold. And when it is more than the emergency threshold value, it is judged that the LED 30 is normal, and when the voltage of the predetermined number of LEDs 30 of the LED light source unit 19 is less than the emergency threshold value, the LED 30 of the LED light source unit 19 is short-circuited. Judge as failure.

  Further, after the lapse of time stipulated by law, the LED 30 of the LED light source unit 19 is intermittently lit, so the LED abnormality detection unit 17 sets a threshold value for detecting abnormality of the LED light source unit. The value is smaller than the threshold value when the LED 30 is continuously lit. This is because when the LED 30 is controlled to be intermittently lit, the average value of the voltage of the LED 30 is smaller than that during continuous lighting. For example, the voltage at the time of intermittent lighting and the time of astigmatism is calculated by moving average, and the abnormality of the LED 30 is determined by whether or not the value is equal to or higher than the threshold value at the time of intermittent lighting. Further, when the LED 30 of the LED light source unit 19 is intermittently lit, the detection of the abnormality of the LED 30 of the LED light source unit 19 may be stopped. This is because when the LED 30 is intermittently lit, the voltage at the time of lighting and when the LED 30 is not stable is unstable. Therefore, the abnormality of the LED 30 is detected only when the voltage of the LED 30 of the LED light source unit 19 is stable. I do. Thereby, the erroneous determination of abnormality of LED30 of the LED light source part 19 can be suppressed.

  In the above description, the case where the LED 30 of the LED light source unit 19 is continuously turned on at all times when power is supplied from the commercial power supply 11 and the commercial power supply 11 is intermittently turned on in the event of a power failure has been described. Needless to say, the present invention can also be applied to the case where an LED is intermittently lit in order to notify the abnormality when an abnormality such as a power failure occurs. Note that LEDs that are intermittently lit when an abnormality such as a fire or power failure occurs can be lit continuously for regular LED or battery inspection, and the threshold value is changed for this continuous lighting and intermittent lighting. This is also included in the present embodiment.

  According to the embodiment of the present invention, the abnormality detection control of the LED 30 of the LED light source unit 19 is detected differently between the continuous lighting and the intermittent lighting of the LED light source unit, and the abnormality of the LED 30 of the LED light source unit 19 is detected. Increases the accuracy of abnormality detection and can detect more reliably.

  The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 11 ... Commercial power supply, 12 ... Rectifier circuit, 13 ... Power supply monitoring circuit, 14 ... Constant power circuit, 15 ... Charging circuit, 16 ... Constant LED lighting circuit, 17 ... LED abnormality detection part, 18 ... Power supply circuit, 19 ... LED light source 20 ... constant current feedback circuit, 21 ... battery, 22 ... lighting control circuit, 23 ... microcomputer, 25 ... emergency power circuit, 26 ... IC, 27 ... switch element, 29 ... LED lighting device, 30 ... LED, 31 ... Current detection resistor, 32 ... Calculation unit, 33 ... Current setting unit, 34 ... Switch, 35 ... Safety circuit

Claims (3)

An LED light source unit;
With constant power circuit;
A battery that is constantly charged by a power circuit;
An LED lighting circuit for lighting the LED by supplying DC power from the battery to the LED light source unit;
A lighting control unit that switches a lighting state of the LED of the LED light source unit between continuous lighting and intermittent lighting;
An LED abnormality detection unit for detecting an abnormality of the LED of the LED light source unit;
An abnormality detection control unit that varies the abnormality detection control of the LED abnormality detection unit between continuous lighting and intermittent lighting of the LED of the LED light source unit;
An LED lighting device comprising:   When the LED of the LED light source unit is intermittently lit, the LED abnormality detection unit has a threshold value for controlling the abnormality of the LED of the LED light source unit that is smaller than a threshold value when the LED of the LED light source unit is continuously lit. The LED lighting device according to claim 1, wherein:   The LED lighting device according to claim 1, wherein the LED abnormality detection unit stops the abnormality detection control of the LED of the LED light source unit when the LED of the LED light source unit is intermittently lit.

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