LED tube lamp

Abstract

To provide an LED straight tube lamp capable of coping with both of both-side connection and one-side connection of an external power source with a simple constitution.SOLUTION: An LED straight tube lamp 10 includes: a housing 2; a pair of mouth pieces 3 disposed on both ends in a longitudinal direction, of the housing 2; a first terminal pin 1a and a second terminal pin 1b disposed on one of the pair of mouth pieces 3; a third terminal pin 1c and a fourth terminal pin 1d disposed on the other of the pair of mouth pieces 3; a power source device 4 connected to the first terminal pin 1a, and converting AC voltage supplied through the first terminal pin 1a, and any of the second to fourth terminal pins 1b-1d into DC voltage; an LED 5; and a switch 7 for switching electric conduction of the power source device 4 and the second terminal pin 1b, and electric conduction of the power source device 4 and the third terminal pin 1c.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an LED tube lamp that is connected to a pair of sockets. [Background technology]

[0002] Light emitting diode (LED) lighting fixtures that use LED elements are becoming more common. One type of LED lighting fixture is a straight-tube LED lamp that is attached to a straight-tube fluorescent light socket and receives power from the socket to light up the LED element.

[0003] For example, Japanese Patent No. 4328379 discloses an LED module fluorescent lamp (LED fluorescent lamp) that can be used in a fluorescent lamp socket with a ballast and that uses an already installed fluorescent lamp frame as is. This LED fluorescent lamp includes a main body and fixed covers at both ends of the main body. Each of the fixed covers at both ends is provided with a connection pin. An LED module and a driving circuit are provided in the main body. The driving circuit includes a first power input unit and a second power input unit that are electrically connected to the connection pins of the fixed covers at both ends, a driving unit, and a feedback unit. The first power input unit and the second power input unit each include a protection unit that prevents overvoltage and overcurrent of the input power, a noise elimination unit that eliminates noise in the output power of the protection unit, and a smoothing unit that smoothes the output power of the noise elimination unit. When power is applied to one of the first power input unit or the second power input unit, there is no outflow of power from the second power input unit or the first power input unit on the opposite side, so that bidirectional input power processing that is safe even if the human body comes into contact with it is possible.

[0004] Utility Model Registration No. 3214340 discloses an LED lamp tube that can be conductive at one or both ends by two conductive pins connected to an external power source. The LED lamp tube has two conductive pin groups, a polarity conversion circuit module, a step-up / step-down circuit module, and an LED light-emitting unit. Each conductive pin group consists of two pins. The polarity conversion circuit module includes two voltage conversion devices (bridge rectifiers), and the conductive pin groups are connected to the two voltage conversion devices. The step-up / step-down circuit module is electrically connected to the polarity conversion circuit module to convert AC to DC, and the LED light-emitting unit is electrically connected to the step-up / step-down circuit module to receive DC. An external power source (commercial AC voltage) passes through one of the voltage conversion devices (bridge rectifiers) from two of the pins, and the current is converted by the step-up / step-down circuit module and transmitted to the LED light-emitting unit. This makes it possible to adapt to a one-end power supply method or a two-end power supply method. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4328379 [Patent Document 2] Utility Model Registration No. 3214340 Summary of the Invention [Problem to be solved by the invention]

[0006] The conventional LED tube lamp described above has a configuration with two circuits for power input to accommodate both cases where the external power supply is connected to the pins on both sides and where the external power supply is connected to only the pins on one side, which increases the number of parts and makes the structure complicated.

[0007] An object of the present invention is to provide an LED straight tube lamp that has a simple configuration and is compatible with both double-sided and single-sided connection of an external power source. [Means for solving the problem]

[0008] An LED tube lamp in an embodiment of the present invention includes a tubular housing, a pair of bases provided at both longitudinal ends of the housing, a first terminal pin and a second terminal pin provided on one of the pair of bases, a third terminal pin and a fourth terminal pin provided on the other of the pair of bases, a power supply device connected to the first terminal pin inside the housing and converting an AC voltage supplied via the first terminal pin and any of the second to fourth terminal pins into a DC voltage, an LED that emits light by the DC voltage output from the power supply device, and a switch that switches between electrical conductivity between the power supply device and the second terminal pin and electrical conductivity between the power supply device and the third terminal pin.

[0009] The LED tube lamp is configured such that the power supply device is connected to one of the four terminal pins at both ends, the first terminal pin, and a switch is used to switch between electrical continuity between the power supply device and the second terminal pin on the same side as the first terminal pin and electrical continuity between the power supply device and the third terminal pin on the opposite side of the first terminal pin. When an external power source is connected to the terminal pins on both sides, the first terminal pin and the third terminal pin are connected to the external power source. In this case, the switch can connect the power supply device to the first terminal pin and the third terminal pin and disconnect it from the second terminal pin. When an external power source is connected to the terminal pin on one side, the first terminal pin and the second terminal pin are connected to the external power source. In this case, the switch can connect the power supply device to the first terminal pin and the second terminal pin and disconnect it from the third terminal pin. In this way, in both cases of power input from the terminal pins on both sides and power input from the terminal pin on one side, the input path between the external power source and the power supply device can be appropriately established by switching the switch. Therefore, with a simple configuration, it is possible to provide an LED straight tube lamp for both double-sided and single-sided connection to an external power source.

[0010] The switch may be configured to be operable from the outside of the housing. This allows the switch to be operated from the outside to switch between a mode corresponding to connection of an external power source to the terminal pins on both sides of the LED tube lamp and a mode corresponding to connection of an external power source to the terminal pins on one side. For example, when installing the LED tube lamp, an operator can determine whether the external power source is connected on both sides or one side and switch by the switch.

[0011] The LED tube lamp may further include a first detection unit that detects that the second terminal pin is connected to an external AC power supply, a second detection unit that detects that the third terminal pin is connected to an external AC power supply, and a switch control unit that, when the first detection unit detects that the second terminal pin is connected to the external AC power supply, controls the switch to establish electrical continuity between the power supply device and the second terminal pin and cuts off the continuity between the power supply device and the third terminal pin, and, when the second detection unit detects that the third terminal pin is connected to the external AC power supply, controls the switch to establish electrical continuity between the power supply device and the third terminal pin and cuts off the continuity between the power supply device and the second terminal pin.

[0012] According to the above configuration, the first detection unit, the second detection unit, and the switch control unit can determine whether power is being input from both sides or one side, and automatically switch the switch so as to appropriately establish a path between the power supply device and an external power source. Effect of the Invention

[0013] According to the present invention, it is possible to provide an LED tube lamp that has a simple configuration and is compatible with both double-sided and single-sided connection of an external power source. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a bottom view showing a configuration example of an LED tube lamp according to a first embodiment. [Diagram 2] A diagram showing an example of the circuit configuration of the LED tube lamp shown in Figure 1. [Diagram 3] A diagram showing an example when an external power supply is connected to one side [Figure 4] A diagram showing an example when external power supplies are connected on both sides [Diagram 5] Another example of a case where an external power supply is connected on both sides [Figure 6] An enlarged view of the area around switch 7 shown in Figure 1. [Figure 7] FIG. 11 is a bottom view showing a configuration example of an LED tube lamp in embodiment 2. [Figure 8] A diagram showing an example of the circuit configuration of the LED tube lamp shown in Figure 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated. In order to make the description easier to understand, the drawings referred to below show the configuration in a simplified or schematic manner, and some of the components are omitted.

[0016] [Embodiment 1] FIG. 1 is a bottom view showing an example of the configuration of an LED tube lamp 10 according to the first embodiment. The LED tube lamp 10 is connected to a pair of sockets S1 and S2. The sockets S1 and S2 have the same shape as a fluorescent lamp socket. That is, the LED tube lamp 10 is an LED lamp that can be connected to a fluorescent lamp socket. The LED tube lamp 10 includes a tubular housing 2 and a pair of bases 3 provided at both ends of the housing 2 in the longitudinal direction. One of the pair of bases 3 is provided with a first terminal pin 1a and a second terminal pin 1b. The other base is provided with a third terminal pin 1c and a fourth terminal pin 1d. When viewed from the longitudinal direction, the first terminal pin 1a and the third terminal pin 1c are disposed at corresponding positions, and the second terminal pin 1b and the fourth terminal pin 1d are disposed at corresponding positions. The first to fourth terminal pins 1a to 1d protrude outward in the longitudinal direction from the base 3. The first to fourth terminal pins 1a to 1d are structured so as to be insertable into a fluorescent lamp socket.

[0017] The shapes of the first to fourth terminal pins 1a to 1d of the LED tube lamp 10 are not limited to these, but may be, for example, a shape that can be attached to an existing fluorescent lamp socket such as G5, G13, R17d, or Rx17d, or may be a base shape such as JEL801 or others.

[0018] The LED tube lamp 10 includes a power supply 4 and an LED 5 in a housing 2. The power supply 4 is connected to the first terminal pin 1a. The power supply 4 converts AC voltage supplied from an external power source into DC voltage. The voltage of the external power source is supplied via the first terminal pin 1a and the second terminal pin 1b, or the first terminal pin 1a and the third terminal pin 1c. The power supply 4 is connected to the LED 5 and outputs DC power to the LED 5. In the example shown in FIG. 1, the power supply 4 and the LED 5 are mounted on a board 6 in the housing 2. The board on which the power supply 4 is mounted may be the same as the board on which the LED 5 is mounted, or may be different.

[0019] The power supply device 4 converts power supplied from an external power source into power for driving the LEDs 5. The power supply device 4 includes, for example, an AC / DC converter. The configuration of the power supply device 4 is not limited to a specific one, but the power supply device 4 may include, for example, a rectifier circuit and a smoothing circuit. The power supply device 4 may also include a step-up / step-down circuit.

[0020] The LED 5 emits light by a DC voltage output from the power supply 4. The housing 2 of the LED tube lamp 10 includes a transparent cover that transmits the light of the LED 5. The light of the LED 5 is irradiated to the outside through the transparent cover of the housing 2.

[0021] The LED tube lamp 10 includes a switch 7. The switch 7 switches between electrical conduction between the power supply device 4 and the second terminal pin 1b and electrical conduction between the power supply device 4 and the third terminal pin 1c. In the example shown in FIG. 1, the switch 7 is configured to be operable from outside the housing 2. That is, an operation part of the switch 7 is exposed to the outside of the housing 2. The operation part of the switch 7 is provided, for example, on the outer periphery of the base 3. This makes it possible to reduce the light of the LED 5 blocked by the switch 7.

[0022] Fig. 2 is a diagram showing an example of a circuit configuration of the LED tube lamp 10 shown in Fig. 1. In the example shown in Fig. 2, the power supply device 4 is connected to the first terminal pin 1a. The power supply device 4 has, as an example, a rectifier circuit 41 and a smoothing capacitor 42. The rectifier circuit 41 may be, for example, a diode bridge.

[0023] A switch 7 is provided between the power supply device 4 and the second terminal pin 1b, and between the power supply device 4 and the third terminal pin 1c. The switch 7 switches between electrical connection and disconnection between the power supply device 4 and the second terminal pin 1b, and between electrical connection and disconnection between the power supply device 4 and the third terminal pin 1c. The switch 7 is switched by, for example, an external operation.

[0024] 2, in either case where the external power source is connected on both sides or one side, the power supply device 4 can be appropriately connected to the external power source by switching the switch 7. A specific example will be described below with reference to FIGS. 3 to 5.

[0025] FIG. 3 is a diagram showing an example in which an external power supply is connected to one side. In this example, the external power supply (for example, a commercial power supply) is connected to the terminal pins 1a and 1b of one of the bases 3 at both ends of the LED tube lamp 10, and is not connected to the terminal pins 1c and 1d of the other base. That is, the AC voltage of the external power supply is input to the two terminal pins 1a and 1b on one side. In this case, the switch 7 is switched so as to electrically connect the power supply device 4 and the second terminal pin 1b, and electrically disconnect the power supply device 4 and the third terminal pin 1c. This allows the AC voltage of the external power supply to be supplied to the power supply device 4. In addition, the terminal pins 1c and 1d to which the external power supply is not connected are electrically disconnected from the power supply device 4, and the voltage supplied from the external power supply is not output to the terminal pins 1c and 1d.

[0026] FIG. 4 is a diagram showing an example in which an external power supply is connected on both sides. In this example, the external power supply is connected to the terminal pin 1a of one of the caps 3 at both ends of the LED tube lamp 10 and the terminal pin 1c of the other cap, and is not connected to the terminal pins 1a and 1d of the cap. That is, the AC voltage of the external power supply is input to the two opposing terminal pins 1a and 1c on both sides of the LED tube lamp 10. In this case, the switch 7 is switched so as to electrically connect the power supply device 4 and the third terminal pin 1c, and electrically disconnect the power supply device 4 and the second terminal pin 1b. This allows the AC voltage of the external power supply to be supplied to the power supply device 4. In addition, the terminal pins 1b and 1d to which the external power supply is not connected are electrically disconnected from the power supply device 4, and the voltage supplied from the external power supply is not output to the terminal pins 1b and 1d.

[0027] FIG. 5 is a diagram showing another example in which an external power supply is connected on both sides. In this example, the external power supply is connected to two terminal pins 1a, 1b of one of the caps 3 at both ends of the LED tube lamp 10 and two terminal pins 1c, 1d of the other cap. That is, the AC voltage of the external power supply is input to the two terminal pins 1a, 1b, 1c, 1d on both sides of the LED tube lamp 10. In this case, as in the case of FIG. 4, the switch 7 is switched so as to electrically connect the power supply device 4 and the third terminal pin 1c and electrically disconnect the power supply device 4 and the second terminal pin 1b. This allows the AC voltage of the external power supply to be supplied to the power supply device 4.

[0028] FIG. 6 is an enlarged view of the vicinity of the switch 7 shown in FIG. 1. In the example shown in FIG. 6, indicators 7a and 7b indicating the operation of the switch 7 are provided near the switch 7 on the surface of the LED tube lamp 10. In the example shown in FIG. 6, information indicating the relationship between the operation position of the switch 7 and the connection form of the external power source is displayed. With such an indication, the worker can appropriately switch the switch 7 according to the connection form of the external power source. In FIG. 6, an operation of moving the switch 7 in one direction (the direction indicated by the arrow U) is displayed to correspond to a form in which the external power source is connected to both sides, and an operation of moving the switch 7 in another direction (the direction indicated by the arrow D) is displayed to correspond to a form in which the external power source is connected to one side.

[0029] In the example shown in Fig. 6, the switch 7 is configured to switch between three states. A first state of the three states is a state in which the power supply device 4 is connected to the second terminal pin 1b and disconnected from the third terminal pin 1c. A second state is a state in which the power supply device 4 is connected to the third terminal pin 1c and disconnected from the second terminal pin 1b. A third state is a state in which the power supply device 4 is disconnected from both the second terminal pin 1b and the third terminal pin 1c. The switch 7 may be configured to switch between one of the first state and the second state.

[0030] [Embodiment 2] Fig. 7 is a bottom view showing an example of the configuration of the LED straight tube lamp 10 in embodiment 2. Fig. 8 is a diagram showing an example of the circuit configuration of the LED straight tube lamp 10 shown in Fig. 7. The LED straight tube lamp 10a shown in Fig. 7 differs from the LED straight tube lamp 10 shown in Fig. 1 in that no switch is provided on the surface of the housing 2. In the LED straight tube lamp 10a, the switch is provided in the housing 2. For example, the switch is provided on the board 6 on which the power supply device 4 in the housing 2 is mounted.

[0031] As shown in Fig. 8, the power supply device 4 is connected to the first terminal pin 1a. The switch 7 switches between electrical conduction between the power supply device 4 and the second terminal pin 1b and electrical conduction between the power supply device 4 and the third terminal pin 1c. These points are the same as those in the first embodiment. In the example shown in Fig. 8, the LED tube lamp 10 further includes a first detection unit 11, a second detection unit 12, and a switch control unit 13. The first detection unit 11, the second detection unit 12, and the switch control unit 13 are mounted on a board 6 in the housing 2, for example.

[0032] The first detection unit 11 detects that the second terminal pin 1b is connected to an external power supply. That is, the first detection unit 11 detects the input of an AC voltage to the second terminal pin 1b. For example, the first detection unit 11 can detect the connection of the external power supply by detecting the voltage of a node on the line between the second terminal pin 1b and the switch 7.

[0033] The second detection unit 12 detects that the third terminal pin 1c is connected to an external AC power supply. That is, the second detection unit 12 detects the input of an AC voltage to the third terminal pin 1c. For example, the second detection unit 12 can detect the connection of the external power supply by detecting the voltage of a node on the line between the third terminal pin 1c and the switch 7. The configurations of the first detection unit 11 and the second detection unit 12 are not limited to a specific one, but can be configured, for example, by a voltage detection circuit.

[0034] The switch control unit 13 controls the switch 7 based on the detection result of the first detection unit 11 and the detection result of the second detection unit 12. The switch control unit 13 is connected to the first detection unit 11 and the second detection unit 12. When the first detection unit 11 detects that the second terminal pin 1b is connected to an external power source, the switch control unit 13 controls the switch 7 to make the power supply device 4 conductive with the second terminal pin 1b and disconnect it from the third terminal pin 1c. When the second detection unit 12 detects that the third terminal pin 1c is connected to an external power source, the switch control unit 13 controls the switch 7 to make the power supply device 4 conductive with the third terminal pin 1c and disconnect it from the second terminal pin 1b. When the connection of an external power source is not detected in either the second terminal pin 1b or the third terminal pin 1c, the switch control unit 13 may control the switch 7 to disconnect the power supply device 4 from both the second terminal pin 1b and the third terminal pin 1c.

[0035] With the configuration shown in Fig. 8, the LED tube lamp 10a can detect whether the external power supply is connected on both sides or one side, and automatically switch the switch 7 so that the connection relationship between the terminal pins 1a to 1d and the power supply device 4 becomes appropriate. This eliminates the need for an operator to perform a switch switching operation. For example, similar to the example shown in Figs. 3 to 5 in the first embodiment, the switch control unit 13 can switch the switch 7 depending on the connection form of the external power supply. This makes it possible to handle both cases where the external power supply is connected on both sides and one side.

[0036] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the above example, the switch 7 is one and has three terminals, but two switches, that is, a switch for switching between conduction and disconnection between the power supply device 4 and the second terminal pin 1b, and a switch for switching between conduction and disconnection between the power supply device 4 and the third terminal pin 1c, may be provided as the switch 7.

[0037] In the above example, the fourth terminal pin 1d is not electrically connected to the circuit inside the housing. The fourth terminal pin 1d may be electrically connected to, for example, the third terminal pin 1c.

[0038] The switch 7 may be a mechanical switch that mechanically switches between disconnection and connection between the wirings, or a semiconductor switch that switches the connection between the wirings on and off by an electrical signal that controls the state of the semiconductor. The switch 1 in the first embodiment is preferably a mechanical switch, and the switch in the second embodiment is preferably a semiconductor switch.

[0039] The power supply device 4, the LED 5, and the switch 7 may be mounted on the same board or on different boards. In the configuration shown in Fig. 8, for example, the power supply device 4, the LED 5, the switch 7, the first detection unit 11, the second detection unit 12, and the switch control unit 13 can be mounted on the same board.

[0040] The configuration of the LED driving circuit is not limited to the above example. For example, the LED tube lamp may further include a dimming circuit for adjusting the light of the LED. [Explanation of symbols]

[0041] 1a 1st terminal pin 1b 2nd terminal pin 1c 3rd terminal pin 1d 4th terminal pin 2. Chassis 3. Base 4 Power supply 5 LED 7. Switch 10 LED tube lamp 11 First detection section 12 Second detection section 13 Switch control section S1, S2 sockets

Claims

1. A tubular housing; A pair of caps provided at both ends of the housing in a longitudinal direction; a first terminal pin and a second terminal pin provided on one of the pair of bases; a third terminal pin and a fourth terminal pin provided on the other of the pair of bases; a power supply device connected to the first terminal pin within the housing and configured to convert an AC voltage supplied via the first terminal pin and any one of the second to fourth terminal pins into a DC voltage; an LED that emits light by the DC voltage output from the power supply device; a switch that switches between electrical conduction between the power supply device and the second terminal pin and electrical conduction between the power supply device and the third terminal pin.

2. The LED tube lamp according to claim 1 , wherein the switch is operable from outside the housing.

3. a first detection unit that detects whether the second terminal pin is connected to an external AC power source; a second detection unit that detects whether the third terminal pin is connected to an external AC power supply; 3. The LED straight tube lamp according to claim 1, further comprising a switch control unit that, when the first detection unit detects that the second terminal pin is connected to an external AC power supply, controls the switch to establish electrical continuity between the power supply device and the second terminal pin and cuts off electrical continuity between the power supply device and the third terminal pin, and when the second detection unit detects that the third terminal pin is connected to an external AC power supply, controls the switch to establish electrical continuity between the power supply device and the third terminal pin and cuts off electrical continuity between the power supply device and the second terminal pin.

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