Lighting devices and emergency lighting fixtures

Abstract

To reduce the size of a lighting device.SOLUTION: A lighting device 1 comprises a common use lighting circuit part 10, an emergency lighting circuit part 11, and a control unit 14. The common use lighting circuit part 10 turns on a light source 2 with a power supplied from a common use power supply P1. The emergency lighting circuit part 11 includes a transformer T1 and a switching element Q1. An emergency power supply P2 is connected with a series circuit of a primary coil N11 of the transformer T1 and the switching element Q1. The light source 2 is connected with a secondary coil N12 of the transformer T1. The control unit 14 controls the switching element Q1 to be in an OFF state when there is no power failure in the common use power supply P1. The control unit 14 performs a switching operation of the switching element Q1 when there is a power failure in the common use power supply P1. When there is a power failure in the common use power supply P1, the emergency lighting circuit part 11 transmits an energy at the primary side of the transformer T1 to the secondary side by the switching operation of the switching element Q1 to turn on the light source 2.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a lighting device and an emergency lighting fixture, and more particularly to a lighting device that is supplied with power from two types of power sources, a normal power source and an emergency power source, to light a light source, and an emergency lighting fixture including the lighting device.

Background Art

[0002] As a conventional example, the light-emitting device described in Patent Document 1 is illustrated. The light-emitting device described in Patent Document 1 is used in an evacuation indicator light device. A housing of the evacuation indicator light device incorporates a lighting device. The lighting device includes a normal lighting circuit that receives power supply from an AC power source such as a commercial power source when the AC power source is energized, and generates DC power to be supplied to a light source circuit. The lighting device also includes an emergency lighting circuit that receives power supply from a storage battery in an emergency such as a power outage, and generates DC power to be supplied to the light source circuit.

[0003] A first switching element is connected between the normal lighting circuit and the light source, and a second switching element is connected between the emergency lighting circuit and the light source. When the AC power source is energized, the first switching element is turned on and the second switching element is turned off, so that DC power is supplied from the normal lighting circuit to the light source to light the light source. In an emergency, the first switching element is turned off and the second switching element is turned on, so that DC power is supplied from the emergency lighting circuit to the light source to light the light source.

Prior Art Literature

Patent Literature

[0004]

Patent Literature 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] The aforementioned lighting device requires a second switching element to switch the power supply path between the emergency lighting circuit and the light source between a conductive state and a disconnected state, which hinders the miniaturization of the lighting device.

[0006] The purpose of this disclosure is to provide a lighting device and an emergency lighting fixture that can be miniaturized. [Means for solving the problem]

[0007] A lighting device according to one aspect of the present disclosure comprises a normal lighting circuit, an emergency lighting circuit, a control unit, and a switching circuit. The normal lighting circuit illuminates a light source with power supplied from a normal power supply. The emergency lighting circuit illuminates the light source with power supplied from an emergency power supply. The switching circuit switches the power supply path from the normal lighting circuit to the light source between a conductive state and a disconnected state. The emergency lighting circuit includes a transformer and a switching element. The switching circuit includes a series circuit of a switch element and a first diode connected between the normal lighting circuit and the light source, the anode of the first diode being connected to the switch element, and the cathode of the first diode being connected to the light source. The emergency power supply is connected to a series circuit of the primary winding of the transformer and the switching element. A smoothing capacitor is connected to the secondary winding of the transformer via a second diode, and the light source is connected to the high-potential terminal of the smoothing capacitor. The control unit operates when the normal power supply is not experiencing a power outage. If no power-off signal is received from an external signaling device Control the switching circuit to a conductive state. When a power-off signal is received from the signaling device, the switching circuit is controlled to a shut-off state. The control unit controls the switching element to the OFF state when the normal power supply is not experiencing a power outage. The control unit controls the switching circuit to the OFF state when the normal power supply is experiencing a power outage. The control unit causes the switching element to switch when the normal power supply is experiencing a power outage. The emergency lighting circuit, when the normal power supply is experiencing a power outage, transmits energy from the primary side of the transformer to the secondary side by the switching operation of the switching element, thereby lighting the light source connected to the secondary winding of the transformer.

[0008] An emergency lighting fixture according to one aspect of the present disclosure comprises a lighting device, a light source, an emergency power supply, and a casing. The casing houses the lighting device, the light source, and the emergency power supply. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide a lighting device and an emergency lighting fixture that can be miniaturized. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is an external perspective view of an emergency lighting fixture according to an embodiment of this disclosure. [Figure 2] Figure 2 is an exploded perspective view of the same emergency lighting fixture. [Figure 3] Figure 3 is a circuit diagram of a lighting device according to an embodiment of the present disclosure. [Figure 4] Figure 4 is a timing chart illustrating the operation of the lighting device described above. [Figure 5] Figure 5 is a circuit diagram of the main part of a lighting device according to Modification 1 of the present disclosure. [Modes for carrying out the invention]

[0011] The lighting device 1 and emergency lighting fixture A1 according to the embodiments of this disclosure will be described in detail with reference to the drawings. However, the figures described in the embodiments below are schematic diagrams, and the ratios of the size and thickness of each component do not necessarily reflect the actual dimensional ratios. Furthermore, the configurations described in the following embodiments are merely examples of this disclosure. This disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of this disclosure can be achieved.

[0012] (1) Overview Figure 3 is a schematic circuit diagram of the lighting device 1 according to this embodiment.

[0013] A lighting device 1 according to an embodiment includes a normal lighting circuit unit 10, an emergency lighting circuit unit 11, and a control unit 14.

[0014] The normal lighting circuit unit 10 lights a light source 2 with power supplied from a normal power supply P1.

[0015] The emergency lighting circuit unit 11 lights the light source 2 with power supplied from an emergency power supply P2.

[0016] The emergency lighting circuit unit 11 includes a transformer T1 and a switching element Q1.

[0017] A series circuit of a primary winding N11 of the transformer T1 and the switching element Q1 is connected to the emergency power supply P2. The light source 2 is connected to a secondary winding N12 of the transformer T1.

[0018] The control unit 14 controls the switching element Q1 to be off when the normal power supply P1 has no power outage.

[0019] The control unit 14 causes the switching element Q1 to perform a switching operation when the normal power supply P1 has a power outage.

[0020] When the normal power supply P1 has a power outage, the emergency lighting circuit unit 11 transmits energy on the primary side of the transformer T1 to the secondary side through the switching operation of the switching element Q1, thereby lighting the light source 2 connected to the secondary winding N12 of the transformer T1.

[0021] Here, "connecting" two circuit components means that the two circuit components are electrically connected, and one or more circuit components may be connected between the two circuit components. Also, in the following description, the transformer T1 provided in the emergency lighting circuit section 11 may be referred to as the first transformer T1, and the switching element Q1 may be referred to as the first switching element Q1. The normal power supply P1 is, for example, a commercial AC power supply of AC100V / 200V, 50Hz / 60Hz. The emergency power supply P2 is a power supply for supplying power to the light source 2 in emergencies such as a power outage of the normal power supply P1. The emergency power supply P2 includes, for example, a power storage section B1 (see Figure 3) having one or more storage batteries.

[0022] When the normal power supply P1 is not experiencing a power outage, the control unit 14 controls the switching element Q1 to the OFF position, thereby stopping the output from the emergency lighting circuit unit 11, and the normal lighting circuit unit 10 lights up the light source 2. On the other hand, when the normal power supply P1 is experiencing a power outage, the control unit 14 switches the switching element Q1, causing the emergency lighting circuit unit 11 to light up the light source 2. As a result, the lighting device 1 can light up the light source 2 both when the normal power supply P1 is not experiencing a power outage and when it is experiencing a power outage.

[0023] Here, when the normal power supply P1 is not experiencing a power outage, the control unit 14 controls the switching element Q1 to turn off, thereby preventing voltage from being generated on the secondary side of the transformer T1. Therefore, unlike conventional lighting devices, there is no need to provide a switch element between the emergency lighting circuit unit 11 and the light source 2, and the number of switch elements between the emergency lighting circuit unit 11 and the light source 2 can be reduced. Consequently, in the lighting device 1 of this embodiment, the lighting device 1 can be miniaturized by reducing the number of switch elements. Furthermore, in the lighting device 1 of this embodiment, the cost can also be reduced by reducing the number of switch elements.

[0024] The emergency lighting fixture A1 according to this embodiment comprises a lighting device 1 according to this embodiment, a light source 2, an emergency power supply P2, and a body A10 (see Figures 1 and 2). The body A10 houses the lighting device 1, the light source 2, and the emergency power supply P2.

[0025] Since the emergency lighting fixture A1 according to this embodiment is equipped with a lighting device 1 according to this embodiment, the emergency lighting fixture A1 can be made smaller.

[0026] (2) Details of the emergency lighting fixture according to the embodiment The emergency lighting fixture A1 according to this embodiment (hereinafter abbreviated as emergency lighting fixture A1) will be described in detail with reference to the drawings. The emergency lighting fixture A1 described below is an emergency exit sign installed at an emergency exit or in a passageway to an emergency exit in a building such as an office or store. However, the emergency lighting fixture A1 according to this embodiment is not limited to an emergency exit sign, and may be, for example, a stairwell guide light installed in a stairwell within a building, or an emergency light installed on the ceiling of a room. In the following description, unless otherwise specified, the up and down, front and back, and left and right directions indicated by arrows in Figure 1 are defined as the up and down, front and back, and left and right directions of the emergency lighting fixture A1.

[0027] The emergency lighting fixture A1 comprises a lighting device 1 (hereinafter abbreviated as lighting device 1) according to the embodiment, a main body A10, a light source unit A11, a display block A12, a battery unit BU1 which is an emergency power supply P2, and the like (see Figures 1 and 2).

[0028] The casing A10 is formed from a synthetic resin material into a rectangular box shape with an opening on the front (see Figure 2). The casing A10 houses the lighting device 1, battery unit BU1, terminal block 90, mounting plate 91, and the like.

[0029] The mounting plate 91 is formed in a plate shape from a metal material (see Figure 2). The mounting plate 91 is screwed to the inner bottom surface of the device body A10. The lighting device 1 and the terminal block 90 are screwed to the mounting plate 91 and housed inside the device body A10. The lighting device 1 and the terminal block 90 are electrically connected. The terminal block 90 is electrically connected to the power line that is drawn in from the power hole 96 (see Figure 2) provided on the bottom surface of the device body A10. In other words, the lighting device 1 is electrically connected to the normal power supply P1 (e.g., commercial AC power) through the terminal block 90 and the power line.

[0030] The battery unit BU1 comprises a power storage section B1 (see Figure 3) having one or more rechargeable batteries, and a case housing the power storage section B1. The battery unit BU1 is detachably attached to the mounting plate 91. The battery unit BU1 is electrically connected to the lighting device 1 while attached to the mounting plate 91.

[0031] Display block A12 includes a display panel 92, a light guide plate 93, and a holder 94 (see Figure 2).

[0032] The display panel 92 is formed in the shape of a rectangular flat plate from a translucent synthetic resin material such as acrylic resin or polycarbonate resin. However, the display panel 92 may be formed from a translucent material other than synthetic resin, such as quartz glass. A pictogram 921 for evacuation guidance is displayed on the front surface (display surface 920) of the display panel 92 (see Figure 1).

[0033] The light guide plate 93 is formed in the shape of a rectangular flat plate from a light-transmitting synthetic resin material such as acrylic resin or polycarbonate resin. The light guide plate 93 is positioned behind the display panel 92 so that its front surface faces the rear surface of the display panel 92 (see Figure 2). Light emitted from the light source unit A11 is incident on the upper surface (incident surface 930) of the light guide plate 93. The light incident on the incident surface 930 is guided through the light guide plate 93 and emitted from the front surface of the light guide plate 93. The display panel 92 is then illuminated by the light emitted from the emission surface of the light guide plate 93.

[0034] The holder 94 is formed from a non-transparent synthetic resin material in the shape of a rectangular box (frame) with an open front and top. The holder 94 holds the display panel 92 and the light guide plate 93, with the display panel 92 positioned in front of the light guide plate 93 (see Figure 2).

[0035] The display block A12 is attached to the body A10 so as to cover the remaining portion of the opening of the body A10, excluding the upper part where the light source unit A11 is attached (see Figure 1).

[0036] The light source unit A11 includes a light source 2 (see Figure 3), a light guide that guides the light emitted from the light source 2, and a housing 95 that houses the light source 2 and the light guide (see Figure 2).

[0037] The housing 95 is formed in the shape of a long box with its bottom and rear open. The light source 2, LED 21, is mounted on a substrate and housed in one end (right end) along the longitudinal direction of the housing 95. The light guide is formed in the shape of a long rectangular prism. The light guide is housed in the housing 95 with one end face (right end face) along the longitudinal direction facing the LED 21, and its side (bottom) along the longitudinal direction facing the opening in the bottom of the housing 95. A portion of the substrate on which the LED 21 is mounted (hereinafter referred to as the projection 97) protrudes from the rear surface of the housing 95 (see Figure 2).

[0038] The light source unit A11 is attached to the main body A10 by fitting it into the upper front of the main body A10. At this time, the projection 97 is inserted into the connector 98 located in the upper right corner of the main body A10, thereby electrically connecting the light source unit A11 (light source 2) and the lighting device 1 via the connector 98 and electric wires (not shown).

[0039] Furthermore, when the light source unit A11 is attached to the body A10, the incident surface 930 of the light guide plate 93 and the output port of the light source unit A11 face each other in the vertical direction. Therefore, almost all of the light emitted from the output port of the light source unit A11 enters the light guide plate 93 from its incident surface 930. The light that enters the light guide plate 93 travels through the light guide plate 93, undergoes total internal reflection at the rear surface of the holder 94, and is emitted forward from the output surface of the light guide plate 93 to illuminate the display panel 92.

[0040] (3) Details of the lighting device according to the embodiment Next, the lighting device 1 will be described in detail with reference to the circuit diagram in Figure 3.

[0041] As described above, the lighting device 1 includes a normal lighting circuit section 10, an emergency lighting circuit section 11, a control section 14, and the like. Furthermore, the lighting device 1 also includes a charging circuit section 12, a switching circuit section 13, a rectifier circuit 40, an input capacitor 41, a control power supply section 42, a power failure detection section 43, a current detection section 44, a voltage detection section 45, and the like.

[0042] The rectifier circuit 40 is a diode bridge. The rectifier circuit 40 full-wave rectifies the AC voltage input from the normal power supply P1 (for example, a sinusoidal voltage with a frequency of 50Hz or 60Hz and an effective value of 100V). The pulsating voltage output from the rectifier circuit 40 is smoothed by an input capacitor 41, which is an electrolytic capacitor. The DC voltage smoothed by the input capacitor 41 is then input to the normal lighting circuit section 10.

[0043] (3-1) Regular lighting circuit section The normal lighting circuit section 10 has a so-called isolated flyback converter, which includes a second transformer T2, a second switching element Q2, a diode D1, and a smoothing capacitor C1.

[0044] The first end of the primary winding N21 of the second transformer T2 is electrically connected to the high-potential terminal of the input capacitor 41, and the second end of the primary winding N21 is electrically connected to the drain terminal of the second switching element Q2. The second switching element Q2 is an N-channel field-effect transistor. The source terminal of the second switching element Q2 is electrically connected to the low-potential terminal of the input capacitor 41. The gate terminal of the second switching element Q2 is electrically connected to the converter control unit 30.

[0045] The second transformer T2 has two secondary windings N22 and N23. One end of one secondary winding N22 is electrically connected to the anode of diode D1, and the other end of the other secondary winding N22 is electrically connected to the low-potential terminal of smoothing capacitor C1. Also, the high-potential terminal of smoothing capacitor C1 is electrically connected to the cathode of diode D1. Furthermore, the high-potential terminal of smoothing capacitor C1 is electrically connected to the anode of LED21 via power supply path W1. Also, the low-potential terminal of smoothing capacitor C1 is electrically connected to the cathode of LED21 via two electrically series-connected sensing resistors R21 and R22.

[0046] The converter control unit 30 is composed of an integrated circuit. The converter control unit 30 PWM controls the second switching element Q2 to match the current flowing through the LED 21 to a first target value. However, the converter control unit 30 and the second switching element Q2 may be composed of a single integrated circuit.

[0047] As described above, the normal lighting circuit section 10 includes an isolated second transformer T2 and a second switching element Q2. The normal power supply P1 is connected to a series circuit of the primary winding N21 of the second transformer T2 and the second switching element Q2. The light source 2 (LED 21) is connected to the secondary winding N22 of the second transformer T2. The normal lighting circuit section 10 transmits energy from the primary side of the second transformer T2 to the secondary side through the switching operation of the second switching element Q2, thereby lighting the light source 2 (LED 21) connected to the secondary winding N22 of the second transformer T2.

[0048] Here, the current flowing through LED21 is detected by the current detection unit 44. The current detection unit 44 outputs a voltage (first detection voltage Vx1) proportional to the current flowing through LED21 by differential amplification of the voltage across the high-potential detection resistor R21.

[0049] The first detection voltage Vx1 is input to the reference terminal of the shunt regulator U1 included in the normal lighting circuit section 10. The anode terminal of the shunt regulator U1 is electrically connected to the low-potential terminal of the smoothing capacitor C1. The cathode terminal of the shunt regulator U1 is electrically connected to the low-potential input terminal of the photocoupler 31 and one end of resistor R2. The high-potential input terminal of the photocoupler 31 is electrically connected to the other end of resistor R2 and one end of resistor R1. The other end of resistor R1 is electrically connected to the constant voltage circuit 32. The resistor R2 connected between the two input terminals of the photocoupler 31 plays the role of supplying the minimum cathode current to the shunt regulator U1.

[0050] However, when the cathode current flowing into the cathode terminal is greater than or equal to the minimum cathode current, the shunt regulator U1 conducts, and a forward current flows through the light-emitting diode of the photocoupler 31. The forward current flowing through the light-emitting diode is proportional to the voltage value of the first detection voltage Vx1 (the magnitude of the current flowing through LED21). Also, the output current of the photocoupler 31 (the collector current of the phototransistor) is proportional to the forward current of the light-emitting diode.

[0051] Here, the output terminal of the photocoupler 31 is electrically connected to the converter control unit 30. In other words, the converter control unit 30 receives a first detection voltage Vx1, which is proportional to the current flowing through the LED 21, via the photocoupler 31, and feedback-controls the second switching element Q2 to match the first detection voltage Vx1 to the target voltage. As a result, the normal lighting circuit unit 10 can match the current flowing through the LED 21 to the first target value.

[0052] Incidentally, when the lighting device 1 according to this embodiment is used in an emergency lighting fixture A1, there is a need to operate the charging circuit 12 while turning off the light source 2 (LED 21) when the normal power supply P1 is not experiencing a power outage. Furthermore, as an example of when an emergency lighting fixture, specifically an exit sign, can be turned off, Article 28-3, Paragraph 4, Item 2 of the Fire Service Act Enforcement Regulations and the guidelines state that it is permitted to turn off an exit sign during showtime in a movie theater "when it is installed in a location where darkness is particularly necessary depending on the usage."

[0053] In this embodiment, the lighting device 1 can turn off the LED 21 when the normal power supply P1 is not experiencing a power outage by having the control unit 14 control the switching circuit unit 13 to turn off the switch element 131 inserted in the power supply line W1. If the LED 21 is turned off while the normal power supply P1 is energized, the first detection voltage Vx1 becomes zero. Therefore, in this embodiment, the voltage detection unit 45 outputs a second detection voltage Vx2, which is proportional to the output voltage of the normal lighting circuit unit 10 (voltage across the smoothing capacitor C1), to the reference terminal of the shunt regulator U1. However, the voltage detection unit 45 is configured to make the second detection voltage Vx2 lower than the first detection voltage Vx1 when the normal lighting circuit unit 10 is lighting the LED 21.

[0054] In other words, when the normal lighting circuit section 10 is lighting the LED 21, the converter control section 30 PWM controls the second switching element Q2 according to the first detection voltage Vx1, not the second detection voltage Vx2. At this time, the converter control section 30 PWM controls the second switching element Q2 so that the current flowing through the LED 21 matches the first target value.

[0055] On the other hand, if the charging circuit 12 continues to charge the energy storage unit B1 while the LED 21 is turned off, the first detection voltage Vx1 becomes zero (in other words, the first detection voltage Vx1 becomes lower than the second detection voltage Vx2), so the converter control unit 30 performs PWM control of the second switching element Q2 in accordance with the second detection voltage Vx2.

[0056] (3-2) Charging circuit section The charging circuit section 12 has a so-called isolated flyback converter, which includes a second transformer T2, a second switching element Q2, a diode D2, and a smoothing capacitor C2. However, the charging circuit section 12 shares a portion of the second transformer T2 and the second switching element Q2 with the normal lighting circuit section 10.

[0057] One end of the secondary winding N23 of the second transformer T2 is electrically connected to the anode of diode D2, and the other end of the secondary winding N23 is electrically connected to the low-potential terminal of smoothing capacitor C2. Also, the high-potential terminal of smoothing capacitor C2 is electrically connected to the cathode of diode D2. Furthermore, the high-potential terminal of smoothing capacitor C2 is electrically connected to the constant voltage circuit 32, the constant current circuit 33, the control power supply unit 42, and the power failure detection unit 43. In addition, the low-potential terminal of smoothing capacitor C2 is electrically connected to the cathode of LED21 via two detection resistors R21 and R22.

[0058] The constant current circuit 33 uses the voltage across the smoothing capacitor C2 as its power source to supply a constant charging current to the energy storage unit B1. The energy storage unit B1 is charged by the charging current supplied from the constant current circuit 33. In other words, in this embodiment, the emergency power supply P2 includes the energy storage unit B1, and the lighting device 1 further includes a charging circuit unit 12 that charges the energy storage unit B1 with power supplied from the normal power supply P1. Since the charging circuit unit 12 charges the energy storage unit B1 while the normal power supply P1 is energized, in the event of a power outage of the normal power supply P1, the emergency lighting circuit unit 11 can light up the light source 2 with power supplied from the energy storage unit B1.

[0059] Furthermore, in this embodiment, the charging circuit section 12 includes a secondary winding N23, which is a charging winding connected to the secondary side of the second transformer T2, and the energy storage section B1 is connected to this secondary winding N23 (charging winding). As a result, in this embodiment, the energy storage section B1 can be charged by the energy transmitted from the primary side to the secondary side of the second transformer T2 by the switching operation of the second switching element Q2.

[0060] (3-3) Emergency lighting circuit section The emergency lighting circuit section 11 includes, for example, a flyback converter. The emergency lighting circuit section 11 comprises a first transformer T1, a first switching element Q1, diodes D3 and D4, and smoothing capacitors C3 and C4.

[0061] The first end of the primary winding N11 of the first transformer T1 is electrically connected to the positive terminal of the energy storage unit B1, and the second end of the primary winding N11 is electrically connected to the drain terminal of the first switching element Q1. The first switching element Q1 is an N-channel field-effect transistor. The source terminal of the first switching element Q1 is electrically connected to the negative terminal of the energy storage unit B1. The gate terminal of the first switching element Q1 is electrically connected to the control IC 20.

[0062] The first transformer T1 has two secondary windings N12 and N13. One end of secondary winding N12 is electrically connected to the anode of diode D3, and the other end of secondary winding N12 is electrically connected to the low-potential terminal of smoothing capacitor C3. Also, the high-potential terminal of smoothing capacitor C3 is electrically connected to the cathode of diode D3. Furthermore, the high-potential terminal of smoothing capacitor C3 is electrically connected to the anode of LED21 via power supply path W1. Also, the low-potential terminal of smoothing capacitor C3 is electrically connected to the cathode of LED21 via two electrically series-connected sensing resistors R21 and R22.

[0063] The control IC 20 is composed of an integrated circuit. The control IC 20 operates by receiving a control voltage Vcc from the control power supply unit 42. The control IC 20 performs PWM control on the first switching element Q1, causing the emergency lighting circuit unit 11 to boost or step down the DC voltage supplied from the energy storage unit B1 and output it. Here, the control IC 20 takes in the voltage across the detection resistor R22 (third detection voltage Vx3), which is proportional to the current flowing through the LED 21, and performs PWM control on the first switching element Q1 to match the current flowing through the LED 21 to the second target value. Note that the amount of light emitted when the LED 21 is lit during a power outage is dimmer than the amount of light emitted when the LED 21 is lit when power is supplied, so the second target value of the emergency lighting circuit unit 11 is set to a value smaller than the first target value of the normal lighting circuit unit 10.

[0064] Thus, the lighting device 1 further includes a control IC 20 that controls the switching operation of the first switching element Q1 included in the emergency lighting circuit section 11. When the control unit 14 detects a power outage of the normal power supply P1, it controls the switching circuit section 13 to an off state, then activates the control IC 20, which causes the first switching element Q1 included in the emergency lighting circuit section 11 to start switching. As a result, when the normal power supply P1 fails, the emergency lighting circuit section 11 can light the LED 21 with power supplied from the storage unit B1, which is the emergency power supply P2.

[0065] The control IC 20 has two operating modes: a first mode and a second mode. The first mode is a mode in which the switching operation of the switching element (first switching element) Q1 included in the emergency lighting circuit 11 is stopped. The second mode is a mode in which the switching operation of the switching element (first switching element) Q1 included in the emergency lighting circuit 11 is performed. The control IC 20's operating mode is switched to either the first mode or the second mode by a switching signal S1 input from the control unit 14. When the normal power supply P1 is not failing, the control unit 14 sets the control IC 20's operating mode to the first mode. When the control unit 14 detects a failure in the normal power supply P1, it switches the control IC 20's operating mode from the first mode to the second mode. Thus, when the normal power supply P1 is not failing, the control unit 14 operates the control IC 20 in the first mode and keeps the control IC 20 in standby mode in the first mode. Therefore, compared to the case where the control IC 20 is energized at the moment a power outage of the normal power supply P1 is detected, the time until the control IC 20 can start the switching operation of the first switching element Q1 can be shortened. Thus, in the event of a power outage of the normal power supply P1, the time until the emergency lighting circuit 11 starts lighting the light source 2 can be shortened.

[0066] (3-4) Control power supply unit The control power supply unit 42 has a 3-terminal regulator 420.

[0067] The input terminal of the 3-terminal regulator 420 is connected to the cathode of diode D6. The anode of diode D6 is connected to the high-potential terminal of smoothing capacitor C2. The input terminal of the 3-terminal regulator 420 is also connected to the high-potential terminal of smoothing capacitor C4. The GND terminal of the 3-terminal regulator 420 is connected to the low-potential terminals of smoothing capacitors C2 and C4.

[0068] Therefore, when the normal power supply P1 is not experiencing a power outage and the charging circuit section 12 is operating, the voltage across the smoothing capacitor C2 is applied to the input terminal of the three-terminal regulator 420, causing the three-terminal regulator 420 to output a control voltage Vcc.

[0069] On the other hand, when the normal power supply P1 is out of service and the emergency lighting circuit 11 is operating, the voltage across the smoothing capacitor C4 is applied to the input terminal of the three-terminal regulator 420, and the three-terminal regulator 420 outputs a control voltage Vcc.

[0070] The control power supply unit 42 outputs a control voltage Vcc to the control unit 14 and the control IC 20, etc.

[0071] (3-5) Switching circuit section The switching circuit section 13 includes a drive circuit 130, a switching element 131, a capacitor 132, a resistor 133, a switching element 134, a diode D5, and the like.

[0072] The switching element 131 is a P-channel field-effect transistor. The source terminal of the switching element 131 is electrically connected to the high-potential output terminal of the normal lighting circuit section 10 (the high-potential terminal of the smoothing capacitor C1). The drain terminal of the switching element 131 is electrically connected to the anode of the LED 21 via the diode D5. In other words, the switching element 131 is inserted into the power supply path W1 and can selectively switch the power supply path W1 between a conducting state and a disconnected state. To put it another way, the lighting device 1 includes a switching circuit section 13 that switches the power supply path W1 from the normal lighting circuit section 10 to the light source 2 between a conducting state and a disconnected state.

[0073] Capacitor 132 and resistor 133 are electrically connected in parallel between the source and gate terminals of the switch element 131. In other words, the voltage across capacitor 132 is applied between the source and gate terminals of the switch element 131, so as the voltage across capacitor 132 increases, the drain-source impedance of the switch element 131 decreases.

[0074] The drive circuit 130 has two transistors TR1 and TR2, and two resistors R11 and R12. Both transistors TR1 and TR2 are pnp bipolar transistors. The emitter of one transistor TR1 is electrically connected to the gate terminal of the switch element 131. The collector of transistor TR1 is electrically connected to the base of the other transistor TR2. The base of transistor TR1 is electrically connected to the emitter of transistor TR2 and one end of resistor R11. The other end of resistor R11 is electrically connected to the gate terminal of the switch element 131. The collector of the other transistor TR2 is electrically connected to the low-potential terminal of the detection resistor R22.

[0075] The drive circuit 130 configured as described above functions as a constant current circuit that supplies a constant current through the capacitor 132 or the resistor 133.

[0076] The switching element 134 is an NPN bipolar transistor. The collector of the switching element 134 is electrically connected to the collector of transistor TR1 and the base of transistor TR2 via resistor R12. The emitter of the switching element 134 is electrically connected to the collector of transistor TR2 and the low-potential terminal of the detection resistor R22. The base of the switching element 134 is electrically connected to the control unit 14. In other words, the switching element 134 is turned on and off by the control unit 14, as will be described later. While the switching element 134 is on, the drive circuit 130 operates and the switching element 131 is maintained in the on state (conducting state). On the other hand, while the switching element 134 is off, the drive circuit 130 stops and the switching element 131 is maintained in the off state (cutoff state). Note that the circuit configuration of the switching circuit section 13 shown in Figure 3 is an example, and the circuit configuration of the switching circuit section 13 can be changed as appropriate.

[0077] (3-6) Control Unit The control unit 14 has a microcontroller. The control unit 14 operates by receiving a control voltage Vcc from the control power supply unit 42.

[0078] The control unit 14 receives a power outage detection signal S2 from the power outage detection unit 43 indicating whether or not there is a power outage. The power outage detection unit 43 has a Zener diode ZD1 and a resistor R31. The cathode terminal of the Zener diode ZD1 is electrically connected to the high-potential output terminal of the charging circuit unit 12 (the high-potential terminal of the smoothing capacitor C2). The anode of the Zener diode ZD1 is electrically connected to the negative terminal of the energy storage unit B1 via the resistor R31. In other words, if the normal power supply P1 is not experiencing a power outage and the charging circuit unit 12 is operating, the Zener diode ZD1 conducts and the voltage across the resistor R31 exceeds a threshold, so the power outage detection unit 43 outputs a high-level power outage detection signal S2. On the other hand, if the normal power supply P1 is experiencing a power outage and the charging circuit unit 12 is not operating, the Zener diode ZD1 does not conduct, so the voltage across the resistor R31 becomes zero, and the power outage detection unit 43 outputs a low-level power outage detection signal S2.

[0079] If the normal power supply P1 is not experiencing a power outage, the control unit 14 sets the operating mode of the control IC 20 to the first mode, stops the operation of the emergency lighting circuit unit 11, and controls the switching circuit unit 13 to a conductive state. As a result, the normal lighting circuit unit 10 lights the light source 2 with power from the normal power supply P1.

[0080] On the other hand, if the normal power supply P1 fails, the control unit 14 controls the switching circuit unit 13 to an off state, then switches the operating mode of the control IC 20 from the first mode to the second mode, and starts the operation of the emergency lighting circuit unit 11. As a result, the emergency lighting circuit unit 11 lights up the light source 2 with power from the emergency power supply P2.

[0081] Furthermore, the control unit 14 monitors the voltage of the energy storage unit B1. The voltage on the positive side of the energy storage unit B1 is input to a voltage follower circuit using an operational amplifier OP1 via resistor R30, and the output signal S3 of the voltage follower circuit is input to the control unit 14. The control unit 14 monitors the voltage of the energy storage unit B1 based on the output signal S3 of the voltage follower circuit. When the emergency lighting circuit 11 is illuminating the light source 2 with power from the energy storage unit B1 during a power outage of the normal power supply P1, the control unit 14 stops the operation of the emergency lighting circuit 11 when the voltage of the energy storage unit B1 falls below a predetermined threshold voltage, thereby suppressing over-discharge of the energy storage unit B1. Note that since the input resistance of the operational amplifier OP1 is large, the loss in the circuit that detects the voltage of the energy storage unit B1 can be reduced by reducing the current flowing from the energy storage unit B1 to the operational amplifier OP1.

[0082] (4) Operation Description The operation of the lighting device 1 of this embodiment will be explained with reference to Figure 4 and the like.

[0083] The following describes the operation of the lighting device 1 when the normal power supply P1 is not interrupted during the period from time t0 to time t3 and from time t4 onward, but when the normal power supply P1 is interrupted during the period from time t3 to time t4. Furthermore, it is assumed that a power-off signal is input to the lighting device 1 from an external signaling device during the period from time t1 to time t2, when the normal power supply P1 is not interrupted.

[0084] During the period from time t0 to time t3, the normal power supply P1 is not experiencing a power outage, so the control unit 14 receives a high-level power outage detection signal S2 from the power outage detection unit 43.

[0085] Furthermore, during the first period TM1 from time t0 to time t1, no power-off signal is input to the control unit 14 from an external signaling device, so the control unit 14 operates in its normal operating mode.

[0086] In the normal operating mode, the control unit 14 instructs the converter control unit 30 to operate the normal lighting circuit unit 10 and the charging circuit unit 12, and also turns on the switching element 134 to switch the switch element 131 to the ON state. In other words, when the normal power supply P1 is not experiencing a power outage, the control unit 14 controls the switching circuit unit 13 to be conductive. In addition, in the normal operating mode, the control unit 14 outputs a switching signal S1 to the control IC 20 that sets the operating mode of the control IC 20 to the first mode. At this time, the control IC 20 stops the switching operation of the first switching element Q1, and the emergency lighting circuit unit 11 is kept in a stopped state. Then, the LED 21 lights up (normal lighting) by the normal lighting circuit unit 10, and the energy storage unit B1 is charged by the charging circuit unit 12.

[0087] Subsequently, during the second period TM2 from time t1 to time t2, if a power-off signal is input to the control unit 14 from an external signaling device, the control unit 14 operates in a permanent power-off mode.

[0088] In the permanent off operating mode, the control unit 14 instructs the converter control unit 30 to operate the normal lighting circuit unit 10 and the charging circuit unit 12, and also turns off the switching element 134 and switches the switch element 131 to the off state. In other words, when the normal power supply P1 is not experiencing a power outage, the control unit 14 controls the switching circuit unit 13 to the off state in response to an externally input off signal. Here, since the normal lighting circuit unit 10 and the charging circuit unit 12 share one second switching element Q2, when the charging circuit unit 12 is operated, the normal lighting circuit unit 10 also operates, but because the switching circuit unit 13 switches the power supply line W1 to the off state, the LED 21 is not lit by the normal lighting circuit unit 10. Furthermore, since the control unit 14 maintains the emergency lighting circuit unit 11 in the stopped state, the LED 21 is not lit by the emergency lighting circuit unit 11 either. However, when the control unit 14 operates in a mode where the LED is always off, the LED 21 can be turned off while continuing to charge the energy storage unit B1.

[0089] Furthermore, if the first switching element Q1 of the emergency lighting circuit 11 is not performing a switching operation, no current flows from the energy storage unit B1 to the secondary side of the first transformer T1. Therefore, there is no need to provide a switch element to interrupt the power supply path W1 between the emergency lighting circuit 11 and the light source 2. Consequently, by omitting the switch element between the emergency lighting circuit 11 and the light source 2, the lighting device 1 can be miniaturized, and the cost of the lighting device 1 can be reduced.

[0090] When the input of the off signal from the signaling device to the control unit 14 stops at time t2, the control unit 14 will operate again in its normal operating mode during the third period TM3 from time t2 to time t3.

[0091] The control unit 14 turns on the switching element 134, switching the switch element 131 to the ON state (i.e., the switching circuit unit 13 to a conductive state). As a result, the lighting device 1 operates in its normal operating mode, which lights the light source 2 (LED 21) while operating the charging circuit unit 12.

[0092] Subsequently, during the fourth period TM4 from time t3 to time t4, if the normal power supply P1 fails, a low-level power failure detection signal S2 is input from the power failure detection unit 43 to the control unit 14, and the control unit 14 operates in emergency operation mode.

[0093] In emergency operation mode, the control unit 14 activates the emergency lighting circuit unit 11 and turns off the switching element 134, switching the switch element 131 to the off state. In other words, when the normal power supply P1 is in a failure state, the control unit 14 controls the switching circuit unit 13 to a shut-off state. The normal lighting circuit unit 10 and the charging circuit unit 12 are shut down when the power supply from the normal power supply P1 is stopped. In addition, in emergency operation mode, the control unit 14 outputs a switching signal S1 to the control IC 20 to switch the operation mode of the control IC 20 from the first mode to the second mode. At this time, the control IC 20 switches the operation mode from the first mode to the second mode, starts the switching operation of the first switching element Q1, and lights up the LED 21 (emergency lighting) with the emergency lighting circuit unit 11.

[0094] Subsequently, at time t4, when the power outage of the normal power supply P1 is restored and power is supplied from the normal power supply P1, a high-level power outage detection signal S2 is input from the power outage detection unit 43 to the control unit 14 during the fifth period TM5 after time t4. Also, during the fifth period TM5, since no power off signal is input to the control unit 14 from an external signaling device, the control unit 14 operates in the normal operating mode.

[0095] In the normal operating mode, the LED 21 lights up (normal lighting) by the normal lighting circuit 10, and the power storage unit B1 is charged by the charging circuit 12.

[0096] (5) Variant The above embodiments are merely one of many embodiments of this disclosure. The above embodiments can be modified in various ways depending on the design, etc., as long as they achieve the objectives of this disclosure.

[0097] The following lists some modifications of the above embodiment. The modifications described below can be combined and applied as appropriate.

[0098] (5-1) Variation 1 The lighting device 1 of Modified Example 1 differs from the lighting device 1 of the above embodiment in that the emergency lighting circuit section 11 has a forward converter. Figure 5 is a circuit diagram of the main part of the lighting device 1 according to Modified Example 1. Note that the configuration other than the emergency lighting circuit section 11 is the same as that of the lighting device 1 of the above embodiment, so the same reference numerals are used for common components and their descriptions are omitted.

[0099] The emergency lighting circuit section 11 has a forward converter circuit configuration and includes a first transformer T1, a first switching element Q1, diodes D7 to D10, inductors L1 and L2, and smoothing capacitors C5 and C6.

[0100] The first end of the primary winding N11 of the first transformer T1 is electrically connected to the positive terminal of the energy storage unit B1, and the second end of the primary winding N11 is electrically connected to the drain terminal of the first switching element Q1. The source terminal of the first switching element Q1 is electrically connected to the negative terminal of the energy storage unit B1. The gate terminal of the first switching element Q1 is electrically connected to the control IC 20.

[0101] The first transformer T1 has two secondary windings N12 and N13.

[0102] One end of the secondary winding N12 is electrically connected to the anode of diode D7, and the other end of the secondary winding N12 is electrically connected to the low-potential terminal of smoothing capacitor C5. In addition, inductor L1 is electrically connected between the high-potential terminal of smoothing capacitor C5 and the cathode of diode D7. Furthermore, the anode of diode D8 is connected to the low-potential terminal of smoothing capacitor C5, and the cathode of diode D8 is connected to the cathode of diode D7. Here, the high-potential terminal of smoothing capacitor C5 is electrically connected to the anode of LED21 via the power supply line W1. Also, the low-potential terminal of smoothing capacitor C5 is electrically connected to the cathode of LED21 via two electrically series-connected detection resistors R21 and R22.

[0103] Furthermore, one end of the secondary winding N13 is electrically connected to the anode of diode D9, and the other end of the secondary winding N13 is electrically connected to the low-potential terminal of smoothing capacitor C6. In addition, an inductor L2 is electrically connected between the high-potential terminal of smoothing capacitor C6 and the cathode of diode D9. The anode of diode D10 is connected to the low-potential terminal of smoothing capacitor C6, and the cathode of diode D10 is connected to the cathode of diode D9. Here, the high-potential terminal of smoothing capacitor C6 is connected to the input terminal of the three-terminal regulator 420, and the low-potential terminal of smoothing capacitor C6 is connected to the GND terminal of the three-terminal regulator 420.

[0104] During a power outage of the normal power supply P1, the control IC 20 performs PWM control on the first switching element Q1, transferring energy from the primary to the secondary side of the first transformer T1. This generates voltages at the smoothing capacitors C5 and C6, respectively, which are either boosted or stepped down from the DC voltage supplied by the energy storage unit B1. As a result, when the normal power supply P1 fails, the emergency lighting circuit 11 can light the LED 21 with power supplied from the energy storage unit B1, which is the emergency power supply P2, and supply a DC voltage to the control power supply unit 42.

[0105] (5-2) Other variations In the above embodiment, the light source 2 is, for example, an LED 21, but it may also be an organic EL or the like.

[0106] In the above embodiment, the lighting device 1 may use a bipolar transistor as the switching element 131 instead of a field-effect transistor. Whether a field-effect transistor or a bipolar transistor is used for the switching element 131, manufacturing costs can be reduced and reliability can be improved.

[0107] In the above embodiment, the emergency lighting fixture A1 is an exit sign, but it may also be an emergency light. In the above embodiment, the normal lighting circuit 10 and the emergency lighting circuit 11 illuminate the same light source 2, but the light source illuminated by the normal lighting circuit 10 and the light source illuminated by the emergency lighting circuit 11 may be different light sources.

[0108] (summary) As described above, the lighting device (1) of the first embodiment comprises a normal lighting circuit section (10), an emergency lighting circuit section (11), and a control unit (14). The normal lighting circuit section (10) lights up the light source (2) with power supplied from the normal power supply (P1). The emergency lighting circuit section (11) lights up the light source (2) with power supplied from the emergency power supply (P2). The emergency lighting circuit section (11) includes a transformer (T1) and a switching element (Q1). The primary winding (N11) of the transformer (T1) and the switching element (Q1) are connected in series to the emergency power supply (P2). The light source (2) is connected to the secondary winding (N12) of the transformer (T1). The control unit (14) controls the switching element (Q1) to turn off when the normal power supply (P1) is not experiencing a power outage. The control unit (14) switches the switching element (Q1) when the normal power supply (P1) is down. The emergency lighting circuit unit (11) switches the energy from the primary side of the transformer (T1) to the secondary side by switching the switching element (Q1) when the normal power supply (P1) is down, thereby lighting the light source (2) connected to the secondary winding of the transformer (T1).

[0109] According to this embodiment, when the normal power supply (P1) is not experiencing a power outage, the control unit (14) controls the switching element (Q1) to turn off, thereby preventing voltage from being generated on the secondary side of the transformer (T1). Therefore, there is no need to provide a switch element between the emergency lighting circuit unit (11) and the light source (2), which reduces the number of switch elements between the emergency lighting circuit unit (11) and the light source (2), and allows for miniaturization of the lighting device (1).

[0110] In the lighting device (1) of the second embodiment, the transformer (T1) is the first transformer (T1), and the switching element (Q1) is the first switching element (Q1). The normal lighting circuit (10) includes an isolated second transformer (T2) and a second switching element (Q2). The normal power supply (P1) is connected to a series circuit of the primary winding (N21) of the second transformer (T2) and the second switching element (Q2). The light source (2) is connected to the secondary winding (N22) of the second transformer (T2). The normal lighting circuit (10) transmits energy from the primary side of the second transformer (T2) to the secondary side by the switching operation of the second switching element (Q2), thereby lighting the light source (2) connected to the secondary winding (N22) of the second transformer (T2).

[0111] According to this embodiment, energy can be transferred from the primary side to the secondary side of the second transformer (T2) by the switching operation of the second switching element (Q2) connected to the primary winding (N21) of the second transformer (T2).

[0112] In the lighting device (1) of the third embodiment, the emergency power supply (P2) includes a power storage unit (B1) as in the second embodiment. The lighting device (1) further includes a charging circuit unit (12) that charges the power storage unit (B1) with power supplied from the normal power supply (P1).

[0113] According to this embodiment, while the normal power supply (P1) is energized, the charging circuit unit (12) charges the energy storage unit (B1). Therefore, in the event of a power outage of the normal power supply (P1), the emergency lighting circuit unit (11) can light the light source (2) with the power supplied from the energy storage unit (B1).

[0114] In the lighting device (1) of the fourth embodiment, in the third embodiment, the charging circuit section (12) includes a charging winding (N13) connected to the secondary side of the second transformer (T2), and the energy storage section (B1) is connected to the charging winding (N13).

[0115] According to this embodiment, the energy storage unit (B1) can be charged by the energy transmitted from the primary side to the secondary side of the second transformer (T2) by the switching operation of the second switching element (Q2).

[0116] The lighting device (1) of the fifth embodiment further comprises a switching circuit unit (13) that switches the power supply path (W1) from the normal lighting circuit unit (10) to the light source (2) between a conductive state and a disconnected state, in any of the first to fourth embodiments. The control unit (14) controls the switching circuit unit (13) to a conductive state when the normal power supply (P1) is not experiencing a power outage. The control unit (14) controls the switching circuit unit (13) to a disconnected state when the normal power supply (P1) is experiencing a power outage.

[0117] According to this embodiment, when the normal power supply (P1) is out of service, the possibility of the current flowing from the emergency lighting circuit (11) to the light source (2) flowing to the normal power supply (P1) can be reduced by controlling the switching circuit (13) to an interrupted state.

[0118] In the lighting device (1) of the sixth embodiment, as in the fifth embodiment, the control unit (14) controls the switching circuit unit (13) to an off state in response to an off signal input from an external source when the normal power supply (P1) is not experiencing a power outage.

[0119] According to this embodiment, by controlling the switching circuit unit (13) to a shut-off state in response to an externally input off signal, the light source (2) can be turned off while the energy storage unit (B1) is being charged.

[0120] The lighting device (1) of the seventh embodiment further comprises a control IC (20) that controls the switching operation of the switching element (Q1) included in the emergency lighting circuit (11), as in the sixth embodiment. When the control unit (14) detects a power outage of the normal power supply (P1), it controls the switching circuit (13) to an off state, then activates the control IC (20) to start the switching operation of the switching element (Q1) included in the emergency lighting circuit (11).

[0121] According to this embodiment, when the normal power supply (P1) fails, the emergency lighting circuit (11) can light the light source (2) with power supplied from the energy storage unit (B1).

[0122] In the lighting device (1) of the eighth embodiment, in the seventh embodiment, the operating mode of the control IC (20) includes a first mode in which the switching operation of the switching element (Q1) included in the emergency lighting circuit unit (11) is stopped, and a second mode in which the switching operation of the switching element (Q1) included in the emergency lighting circuit unit (11) is performed. The control unit (14) sets the operating mode of the control IC (20) to the first mode when the normal power supply (P1) is not experiencing a power outage, and when it detects a power outage in the normal power supply (P1), it switches the operating mode of the control IC (20) from the first mode to the second mode.

[0123] According to this embodiment, when the normal power supply (P1) is not experiencing a power outage, the control IC (20) operates in the first mode, thus shortening the time from the detection of a power outage in the normal power supply (P1) to the start of operation of the control IC (20) in the second mode.

[0124] In the lighting device (1) of the ninth embodiment, in any of the first to eight embodiments, the emergency lighting circuit section (11) has a flyback converter.

[0125] According to this embodiment, a switching element (Q1) connected to the primary winding (N11) of the transformer (T1) performs a switching operation, thereby transferring energy from the primary side to the secondary side of the transformer (T1).

[0126] In the lighting device (1) of the tenth embodiment, in any of the first to eight embodiments, the emergency lighting circuit section (11) has a forward converter.

[0127] According to this embodiment, a switching element (Q1) connected to the primary winding (N11) of the transformer (T1) performs a switching operation, thereby transferring energy from the primary side to the secondary side of the transformer (T1).

[0128] The 11th embodiment of the emergency lighting fixture (A1) comprises a lighting device (1) of any of the 1st to 10 embodiments, a light source (2), an emergency power supply (P2), and a body (A10). The body (A10) houses the lighting device (1), the light source (2), and the emergency power supply (P2).

[0129] According to this embodiment, by providing a lighting device (1) that can be miniaturized, the emergency lighting fixture (A1) can be made smaller.

[0130] The configurations relating to the second to tenth aspects are not essential to the lighting device (1) and can be omitted as appropriate. [Explanation of Symbols]

[0131] 1. Lighting device 2 light source 10 Regular lighting circuit section 11 Emergency lighting circuit section 12 Charging circuit section 13 Switching circuit section 14 Control Unit A1 Emergency lighting fixtures A10 body B1 Power storage unit N11, N21 Primary winding N12, N22 secondary winding N13 Secondary winding (recharge winding) P1 Regular power supply P2 Emergency power supply Q1 Switching element (first switching element) Q2 Second switching T1 Transformer (First Transformer) T2 Second Transformer W1 feed line

Claims

1. A normal lighting circuit section that lights up the light source using power supplied from the normal power supply, An emergency lighting circuit unit that lights up the light source with power supplied from an emergency power source, Control unit and A switching circuit unit that switches the power supply path from the normal lighting circuit unit to the light source between a conductive state and a disconnected state, Equipped with, The emergency lighting circuit section includes a transformer and a switching element. The switching circuit section includes a series circuit of a switch element and a first diode connected between the normal lighting circuit section and the light source. The anode of the first diode is connected to the switching element, and the cathode of the first diode is connected to the light source. The emergency power supply is connected to a series circuit of the primary winding of the transformer and the switching element. A smoothing capacitor is connected to the secondary winding of the transformer via a second diode. The light source is connected to the high-potential terminal of the smoothing capacitor. The control unit controls the switching circuit to a conductive state when the normal power supply is not experiencing a power outage and no power-off signal is received from an external signaling device, and controls the switching circuit to a disconnected state when a power-off signal is received from the signaling device. The control unit controls the switching element to turn off when the normal power supply is not experiencing a power outage. The control unit controls the switching circuit to an interrupted state when the normal power supply is experiencing a power outage. The control unit, when the normal power supply is in a power outage, causes the switching element to perform a switching operation. The emergency lighting circuit unit, when the normal power supply is in a power outage, transmits energy from the primary side of the transformer to the secondary side by the switching operation of the switching element, thereby lighting the light source connected to the secondary winding of the transformer. Lighting device.

2. The transformer is a first transformer, and the switching element is a first switching element. The aforementioned normal lighting circuit section includes an isolated second transformer and a second switching element. The primary winding of the second transformer and the second switching element are connected in series to the aforementioned regular power supply. The light source is connected to the secondary winding of the second transformer. The normal lighting circuit section transmits energy from the primary side of the second transformer to the secondary side by the switching operation of the second switching element, thereby lighting the light source connected to the secondary winding of the second transformer. The lighting device according to claim 1.

3. The aforementioned emergency power supply includes a power storage unit. The system further includes a charging circuit that charges the energy storage unit with power supplied from the aforementioned regular power source. The lighting device according to claim 2.

4. The charging circuit section includes a charging winding connected to the secondary side of the second transformer. The charging winding is connected to the energy storage unit. The lighting device according to claim 3.

5. The emergency lighting circuit further comprises a control IC for controlling the switching operation of the switching element included in the emergency lighting circuit, When the control unit detects a power outage in the normal power supply, it controls the switching circuit to an off state, then activates the control IC, which in turn causes the switching element included in the emergency lighting circuit to start switching. A lighting device according to any one of claims 1 to 4.

6. The operating mode of the control IC includes a first mode in which the switching operation of the switching element included in the emergency lighting circuit is stopped, and a second mode in which the switching operation of the switching element included in the emergency lighting circuit is performed. The control unit sets the operating mode of the control IC to the first mode when the normal power supply is not experiencing a power outage, and when it detects a power outage of the normal power supply, it switches the operating mode of the control IC from the first mode to the second mode. The lighting device according to claim 5.

7. The emergency lighting circuit section has a flyback converter. A lighting device according to any one of claims 1 to 4.

8. The emergency lighting circuit section has a forward converter. A lighting device according to any one of claims 1 to 4.

9. A lighting device according to any one of claims 1 to 4, The aforementioned light source, The aforementioned emergency power supply, A casing housing the aforementioned lighting device, the aforementioned light source, and the aforementioned emergency power supply, Equipped with, Emergency lighting equipment.

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