JP5192835B2 - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device which can maintain a function of a traffic signal even at emergency with a simple structure. <P>SOLUTION: The light-emitting device is provided with a light-emitting part 1 (1a, 1b, 1c) in which a plurality of series circuits 11, 12 in which a current limiting element R and one or more solid light-emitting elements L are connected in series are connected in parallel and a lighting device 2 which is connected to an AC power supply AC and supplies a drive voltage to the light-emitting parts 1 by full-wave rectifying the AC voltage. The light-emitting part 1 is provided with an emergency power supply 3 in which the non-lighting period of the solid light-emitting element of at least one series circuit 12 is shorter than the non-lighting period of the solid light-emitting element of the other series circuit and which can light at least the solid light-emitting element of the series circuit 12 having the shorter non-lighting period at the time of cut-off of the AC power supply AC. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a light emitting device using a solid light emitting element as a light source.

  Conventionally, a light emitting device using a solid light emitting element such as a light emitting diode as a light source has been proposed. As a lighting control method for such a light emitting device, for example, a direct current lighting control method (for example, see Patent Document 1) in which a direct current voltage obtained by rectifying and smoothing an alternating current voltage is applied to a solid state light emitting element, and an alternating voltage is rectified and smoothed. A switching lighting control system (see, for example, Patent Document 2) for lighting by applying a rectangular wave voltage obtained by boosting a DC voltage and switching the boosted DC voltage at a high frequency to a solid-state light emitting element, and solid-state light emission of the AC voltage. There is known a pulse lighting control method in which lighting is performed using only a predetermined section in one cycle of an AC voltage applied to an element.

In recent years, traffic lights using light-emitting diodes as light sources have been widely used instead of conventional traffic lights using light bulbs as light sources. Light-emitting devices used in such traffic lights are easy to use due to the small number of parts. A pulse lighting control system that can be downsized and has a low failure rate is used.
JP 2006-73637 A Japanese Patent Laid-Open No. 11-67471

  By the way, when switching from a traffic signal device using a light bulb as a light source to a light emitting diode, when adopting the pulse lighting control method for a traffic signal device, it is necessary to increase the number of light emitting diodes connected in series in terms of light emission efficiency. Yes, increasing the number of light emitting diodes connected in series increases the voltage required for lighting. This is a system that is suitable for commercial power supply, and in the event of a power outage or disaster, the traffic signal cannot be operated, and it may not be perfect for ensuring traffic safety.

  On the other hand, emergency lighting devices that use secondary batteries, such as emergency lights and guide lights in the event of an emergency, have become widespread in buildings, etc. Considering the power consumption and drive voltage of traffic lights, the system is very large and is not generally adopted.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a light-emitting device that can maintain the function of a traffic signal in an emergency with a simple configuration.

In order to achieve the above object, according to the first aspect of the present invention, as shown in FIG. 1, a plurality of series circuits 11 and 12 in which a current limiting element R and one or more solid state light emitting elements L are connected in series are arranged in parallel. A light-emitting device comprising: a light-emitting unit 1 (1a, 1b, 1c) connected to the light-emitting unit 1; and a lighting device 2 that is connected to an AC power source AC and rectifies the AC voltage in a full wave to supply a drive voltage to the light-emitting unit 1. a is, light emission section 1 is shorter than the non-lighting period of the solid-state light-emitting element L of the series circuits 11 unlighted period of at least one other series circuit 12 solid state light element L, an AC power source AC during the blocking, become features an emergency power supply 3 which can turn on the solid state light emitting element L of the short series circuit 12 of non-lighting periods, the light emitting unit 1, at least one series circuit 12 solid-state light-emitting element L Is less than the number of solid state light emitting elements L of the other series circuit 11. In the light emitting unit 1, the number of the solid state light emitting elements L of the at least one series circuit 12 is one, and the emergency power source 3 is higher than the intrinsic voltage Vf2 by the solid state light emitting elements L of the series circuit 12 having a short non-lighting period. It is characterized by being set to a voltage lower than the intrinsic voltage Vf1 due to the solid state light emitting element L of the series circuit 11 having a long non-lighting period .

The invention of claim 2 is the invention of claim 1, the light emission unit 1 and the lighting device 2 is characterized in that it comprises a lamp 8 to be at least storage (Figure 4).

The invention according to claim 3, characterized in that in the invention of claim 2, the lamp 8, the light emitting portion 1a, 1b, 1c and has openings 9a for face outward, 9b, the 9c, shorter series of unlighted period opening 9a of the solid-state light-emitting element L of the circuit 12, 9b, characterized in that arranged substantially at the center of 9c (FIG. 5 (a), (b)).

The invention according to claim 4, characterized in that in the invention of claim 2, the lamp 8, the light emitting portion 1a, 1b, 1c and has openings 9a for face outward, 9b, the 9c, shorter series of unlighted period solid-state light-emitting element L of the opening 9a of the circuit 12, 9b, characterized in that arranged on the periphery of 9c (FIG. 5 (c)).

A fifth aspect of the present invention, in the invention of any one of claims 2 to 4, light emission portion 1a, 1b, 1 c, lit. device 2, emergency power supplies 3 and the lamp 8, to be used for traffic signal Features (FIG. 4).

According to the first aspect of the present invention, since the number of solid state light emitting elements of some of the series circuits is smaller than the number of solid state light emitting elements of other series circuits, the circuit configuration is simple. When the AC power supply is shut off, the emergency power supply can be used to maintain the minimum function of the light emitting device.

Further, according to the invention billed to claim 1, the voltage of the emergency power supply higher than the unique voltage by the solid state light emitting element of short series circuit of non-lighting period, and solid state light elements of a long series circuit of unlighted period by the below-specific voltage by children, emergency lighting, by only a small circuit with the number of solid state light emitting devices of the series circuit is turned on, less emergency power consumption, a certain time even a small battery or the like Minimum safety can be ensured. Further, since the light source is selected by utilizing the fact that the number of solid-state light-emitting elements connected in series is different, it is not necessary to switch to a special solid-state light-emitting element and can be realized with a simple circuit.

According to invention of Claim 2, the light-emitting device which has the lamp which produces the effect of Claim 1 is realizable.

According to the invention of claim 3, by arranging the series circuit including the solid state light emitting element having a short non-lighting period in the approximate center of the opening, wiring can be easily made and visibility in an emergency can be improved. The effect is obtained.

According to the invention of claim 4, by arranging a series circuit including a solid state light emitting element having a short non-lighting period at the periphery of the opening, visibility in an emergency can be ensured in a relatively wide area, and recognition is performed. The effect that it is easy to obtain is obtained.

According to the invention of claim 5, it is possible to provide a traffic signal device equipped with an emergency power source having the effect of any one of claims 2 to 4 .

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the present embodiment is configured by connecting a plurality of series circuits 11 and 12 formed by connecting a resistor R, which is a current limiting element, and one or more light-emitting diodes L in series. A light emitting unit 1 (1a, 1b, 1c), a lighting device 2 connected to an AC power supply AC, full-wave rectified AC voltage to supply a driving voltage to the light emitting unit 1, and an emergency power source 3. Become.

  The lighting device 2 is composed of, for example, a diode bridge, and full-wave rectifies the AC voltage from the AC power supply AC, and outputs the rectified pulsating voltage V1 to the light emitting unit 1. The lighting device 2 may have another circuit configuration as long as the AC voltage is full-wave rectified.

  The light emitting unit 1 includes a plurality of first series circuits 11 formed by connecting resistors R and a plurality (n in the present embodiment) of light emitting diodes L in series, and these first series circuits 11 are connected in parallel. A second series circuit 12 formed by connecting a resistor R and one light emitting diode L in series is connected in parallel with the circuit 11. The light emitting unit 1 (1a, 1b, 1c) includes switches Sa, Sb, Sc for on / off control. When one of the light emitting units is closed, the first series circuit 11 and the second series circuit are provided. The pulsating voltage Vdc is applied to 12 parallel circuits. In consideration of the light-emitting diodes in the first series circuit 11, the forward voltage per light-emitting diode L is about 2V for red / yellow light-emitting diodes and about 3.5V for blue-green light-emitting diodes. If the AC voltage AC is a commercial power supply with a power supply voltage of 100 V, it is desirable to connect 20 to 30 in series.

  The operation of this embodiment will be described below. As shown in FIG. 2, the light emitting diode L of the first series circuit 11 is lit only when the pulsating voltage Vdc is higher than the forward voltage Vf1 = n × Vf necessary to light the light emitting diode L. Therefore, the lighting state and the non-lighting state are repeated alternately. Here, the current flowing through the light emitting diode is If1.

  Next, the number of light emitting diodes L in the second series circuit 12 is smaller than the number of light emitting diodes L in the first series circuit 11, and therefore the forward voltage Vf 2 is lower than Vf 1, and the second series circuit 12 The current flowing through becomes If2.

  From the lighting device 2, the voltage V1 is supplied to the low voltage conversion circuit 6 for driving the signal control circuit in parallel with the light emitting unit 1, and is converted into a low DC voltage V2 and output. The signal control circuit 7 is driven by the low DC voltage V2, and the lighting and extinguishing of the light emitting unit 1 are controlled by switches Sa, Sb, Sc such as relays based on the output of the signal control circuit 7. The light emitting units 1b and 1c are the same as the configuration and operation of the light emitting unit 1a except that the light emission color of the light emitting diode L is different and the on / off timings of the switches Sb and Sc such as relays are different.

  From the low voltage conversion circuit 6, the emergency power source 3 is charged through a resistor or the like. Here, the emergency power source 3 uses a secondary battery such as a nickel metal hydride battery or a lithium ion battery, but is not limited thereto. The voltage of the emergency power supply 3 is set to be equal to or higher than the voltage at which the light emitting diode L of the second series circuit 12 can be lit.

  As described above, when the commercial power source AC is in an energized state, all the light emitting diodes are controlled to be lighted and the emergency power source 3 is charged based on the state controlled by the signal control circuit 7.

  In the present embodiment, the second series circuit 12 is described as one series. However, a plurality of second series circuits 12 may be provided, and the light emitting diodes in the second series circuit 12 are also described as one. The forward voltage of the light emitting diode is not limited to one as long as it is lower than the voltage of the emergency power supply 3. Moreover, although the example which used resistance R as a current limiting element is described, it cannot be overemphasized that it may be comprised even if it is a constant current element or a constant current circuit.

  Next, description will be made assuming a so-called power failure state in which the commercial power supply AC is cut off. The voltage is not supplied from the commercial power supply AC, and the operation from the commercial power supply AC is not performed. Although the emergency power supply 3 is no longer charged, the signal control circuit 7 can maintain its operation by supplying power from the emergency power supply 3 to the signal control circuit 7 via the rectifying element 4a.

  Further, a voltage is also supplied to the light emitting unit 1 from the emergency power source 3 through the rectifying element 4b. Here, the first series circuit 11 cannot be turned on by the emergency power supply 3 because the forward voltage based on the number of light emitting diodes L in series is set higher than the voltage of the emergency power supply 3. In other words, the power consumption can be automatically reduced by this.

  On the other hand, since the forward voltage of the light emitting diodes in the second series circuit 12 is set lower than the voltage of the emergency power supply 3, only the light emitting diodes connected to the second series circuit 12 can be kept on. .

  As described above, even when the commercial power supply AC is shut off, at least the second series circuit 12 is controlled to be turned off, so that it is possible to prevent all the lights from being turned off.

  For example, the light-emitting unit 1 functions as a traffic light when configured as blue-green 1a, yellow 1b, and red 1c, and functions as a traffic light for sidewalk when only the blue-green 1a and red 1c are configured. In addition, it is considered to be effective in applications that prevent darkness in an emergency in a lighting device that is always / emergency in a building.

(Embodiment 2)
Next, Embodiment 2 of the present invention will be described with reference to FIG. Portions having the same functions as those in FIG. The difference from FIG. 1 is that the number of light-emitting diodes in the second series circuit 12 is n2, not one, and the forward voltage Vf2 (= n2 · Vf) is higher than the voltage of the emergency power supply 3. A booster circuit 5 is provided that boosts and outputs the voltage of the emergency power supply 3 at the time of a power failure. The number n1 of light emitting diodes in the first series circuit 11 is larger than the number n2 of light emitting diodes in the second series circuit 12, and Vf1> Vf2.

  In the second series circuit 12, the forward voltage Vf2 (= n2 · Vf) of the light emitting diode is lower than the forward voltage Vf1 (= n1 · Vf) of the light emitting diode of the first series circuit. It is comprised on condition higher than the voltage of. Accordingly, in the circuit shown in FIG. 1, the light emitting diode cannot be turned on at the time of a power failure. Therefore, in the circuit of FIG. 3, the booster circuit 5 boosts the voltage from the emergency power supply 3 to a voltage that is equal to or higher than the forward voltage Vf2 (= n2 · Vf) of the light emitting diode of the second series circuit 12, and Electric power is supplied to the light emitting unit 1 through the rectifying element 4c.

  In FIG. 3, when the low voltage conversion circuit 6 can be driven by the voltage generated by the booster circuit 5, the rectifying element 4a may be omitted. Further, the rectifying element 4a is connected so as to supply power to the signal control circuit 7 from the emergency power supply 3. However, depending on design conditions, the rectifying element 4a is connected to supply power to the signal control circuit 7 from the output terminal of the booster circuit 5. May be.

(Embodiment 3)
Embodiment 3 of the present invention will be described with reference to FIG. In this embodiment, as shown in FIG. 4, the light emitting unit 1 and the lighting device 2 of the first embodiment are housed in a lamp 8 of a traffic light. The lamp 8 is a substantially oval box having three substantially circular openings 9a, 9b, 9c for allowing the light emitting parts 1a, 1b, 1c to face the outside, and each of the openings 9a, 9b, The light emitting diodes of the light emitting portions 1a, 1b, and 1c are disposed so as to face the entire surface of 9c.

  The color emitted by the light emitting diode is different for each of the openings 9a, 9b, and 9c. In FIG. 4, the left opening 9a is green, the central opening 9b is yellow, and the right opening 9c is red. . Needless to say, the colors emitted from the light emitting diodes and the arrangement thereof are not limited to those described above, and can be changed according to the application of the traffic signal.

  In each of the openings 9a, 9b, and 9c, the light emitting diodes of the first series circuit 11 having a large number are arranged at the peripheral portion, and the light emitting diodes of the second series circuit 12 having a small number are arranged at a substantially center. In this case, the light emitting diode of the second series circuit 12 having a low forward voltage Vf2 has almost no non-lighting period (particularly, in the first embodiment, the emergency power supply 3 is connected through the rectifying element 4b even near the zero cross of the AC power supply AC. Since a current flows through the light emitting diodes of the second series circuit 12, there is substantially no non-lighting period), so the light emitting diodes at the substantially center of the openings 9 a, 9 b, 9 c are (traffic) During the lighting period of the signal, it is lit almost always (as indicated by the black circle in the figure). Therefore, for example, when the moment of an accident is photographed with a video camera of a drive recorder mounted in a taxi or the like, the light emitting diodes at the substantially center of the openings 9a, 9b and 9c are almost always lit. It is possible to recognize the traffic signal state regardless of the shooting interval and timing.

  In addition, since the light emitting diode at the substantially center of each of the openings 9a, 9b, 9c can be lit by the backup battery 3 even in the event of a power failure or the like, (like the black circle in the figure during the traffic signal lighting period) To) lights up. In this way, by making it possible to turn on only the light emitting elements with a small number of series connections even in an emergency, safety measures can be taken so that at least all traffic signal troubles do not occur in an emergency. Thereby, a simple traffic signal system which does not require a large facility and can ensure the minimum safety can be realized.

(Embodiment 4)
FIG. 5 (a) shows an example of the arrangement of the light emitting diodes of the lamp according to the present invention, in which the light emitting diodes of the second series circuit 12 in FIG. 1 are arranged at substantially the center of the lamp. The black circles in the figure are the light emitting diodes of the second series circuit 12, and the white circles are the light emitting diodes of the first series circuit 11.

  FIG. 5B is an example of the arrangement of different light-emitting diodes. When there are a plurality of light-emitting diodes in the second series circuit 12 that can be lit in an emergency as shown in FIG. It is arranged in. The black circles in the figure are the light emitting diodes of the second series circuit 12, and the white circles are the light emitting diodes of the first series circuit 11.

  FIG. 5C is an example of a different arrangement of light emitting diodes. When there are a plurality of light emitting diodes in the second series circuit 12 that can be lit in an emergency as shown in FIG. It is arranged in. The black circles in the figure are the light emitting diodes of the second series circuit 12, and the white circles are the light emitting diodes of the first series circuit 11.

  Needless to say, the arrangement of this embodiment can be applied to the traffic signal shown in FIG. 4 and also to a general lighting device.

It is a circuit diagram which shows the structure of Embodiment 1 of this invention. It is a wave form diagram which shows operation | movement of Embodiment 1 of this invention. It is a circuit diagram which shows the structure of Embodiment 2 of this invention. It is a front view which shows the light-emitting device of Embodiment 3 of this invention. It is a front view which shows the light-emitting device of Embodiment 4 of this invention.

Explanation of symbols

1 Light Emitting Unit 2 Lighting Device 3 Emergency Power Supply (Secondary Battery)
L Light emitting diode (solid state light emitting device)
R resistance (current limiting element)
11 1st series circuit 12 2nd series circuit

Claims (5)

A light emitting portion formed by connecting a series circuit of a current limiting element and one or more solid state light emitter connected in series to the plurality parallel, the calling optical unit an AC voltage by full-wave rectification are connected to an AC power source a driving voltage to a light emitting device and a lighting device that supplies to the light emitting part, at least one of said series circuit of the non-lighting period of the solid-state light-emitting element of the other of said series circuit solid state light emitting devices of less than unlighted period, during interruption of AC power, become features an emergency power supply capable of turning on the solid state light emitter short has the series circuit of the non-lighting periods, the light emitting unit comprises at least The number of solid state light emitting elements of one of the series circuits is smaller than the number of solid state light emitting elements of the other series circuit, and the light emitting unit has at least one solid state light emitting element of the series circuit, Emergency power supply is short before the non-lighting period Higher than the natural voltage by the solid-state light-emitting element of the series circuit, the light emitting device characterized by comprising setting a voltage lower than the intrinsic voltage by the solid-state light-emitting element of long the series circuit of unlighted period. The light emitting device according to claim 1, wherein the light emitting portion and the lighting device is characterized and this with the lamp being at least housed. Claim wherein the lamp is to have an opening for facing said light emitting portion to the outside, the solid-state light-emitting element of short the series circuit of unlighted period characterized that you arranged substantially at the center of the opening 2. The light emitting device according to 2. The lamp has an opening portion for face the light emitting portion to the outside, claim 2 of the solid-state light-emitting element of short the series circuit of unlighted period characterized that you have placed on the periphery of the opening serial mounting of the light-emitting device. The light emitting portion, the lighting device, the emergency power supply and the lamp, the serial placement of the light-emitting device according to any one one of claims 2-4, characterized in that is used for traffic signal.

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