WO2016120823A1

WO2016120823A1 - Light-emitting diode array lamp and fuse unit

Info

Publication number: WO2016120823A1
Application number: PCT/IB2016/050435
Authority: WO
Inventors: Allan Krogh Jensen
Original assignee: Hesalight A/S
Priority date: 2015-01-28
Filing date: 2016-01-28
Publication date: 2016-08-04

Abstract

The invention relates to a lighting device comprising: - an LED tube having a tubular housing having two ends and a platform disposed between said two ends, - an array of LEDs fixed on said platform, - a bi-pin comprising two electrical terminals extending from each end of said tubular housing, - an LED driver circuit fixed inside said tubular housing for the provision of electrical power to the LED array, - an LED fuse unit adapted to be inserted in a glow switch socket in a light fixture, - the LED fuse unit comprising circuitry adapted to vary the current in the light fixture, - in connection with the LED fuse unit a receiving unit adapted to receive a signal input for the circuitry adapted to vary the current and feeding this signal to the circuitry, - the circuitry further being adapted to adapt the current in a predetermined manner in accordance with the signal input received by the receiving unit.

Description

LIGHT-EMITTING DIODE ARRAY LAMP AND FUSE UNIT

TECHNICAL FIELD

The present invention relates to light-emitting diode (LED) array lamps. In particular, the invention pertains to LED array lamps, also called LED tubes, configured for being used as substitutes for traditional fluorescent light tubes. More particularly, the present invention relates to a fuse unit for use with a fluorescent light tube substituting LED tube in a traditional fluorescent light tube fixture. BACKGROUND OF THE INVENTION

Solid-state lighting from semiconductor light-emitting diodes (LEDs) has received much attention in general lighting applications today. Because of its potential for more energy savings, better environmental protection (no hazardous materials used), higher efficiency, smaller size, and much longer lifetime than conventional incandescent bulbs and fluorescent tubes, the LED-based solid-state lighting will be a mainstream for general lighting in the near future. Meanwhile, as LED technologies develop with the drive for energy efficiency and clean technologies worldwide, more will adopt LED lighting for illumination applications.

LEDs have a long operating life of 50,000 hours. This is equivalent to 17 years of service period, assuming operation for eight hours per day, every day. However, several factors may affect the operating life of an LED-based lamp. A high operating temperature is most detrimental to both LEDs and the LED driver that powers the LEDs. While LEDs can operate 50,000 hours under a condition of good thermal management, such as when using an efficient heat sink design, the lamp will not emit light when the LED driver is broken, which happens if high-temperature air accumulates around the LED driver and any of its electronic components fails. In spite of longevity of LEDs, the LED-based linear lighting system can operate only around 25,000 hours. Some issues related to system reliability during service life of an LED-based lighting system also need to be discussed.

In retrofit applications most "LED tubes", i.e. LED array lamps embodied with outer dimensions as traditional fluorescent light tubes, currently available on the market require that the ballast, which is arranged in the existing light armature fixture, to be bypassed in order to work properly, because they are configured for traditional fluorescent light tubes. None of the substituting LED tubes can therefore be dimmed by dimmable ballast for fluorescent tubes.

When installed with bypassed ballast, it is known to use a so called single ended (SEP) LED tube in order to minimize the risk of electric shock during installation in a fixture for fluorescent tubes. Some of the LED tubes currently on the market can be used in fluorescent tube fixtures without bypassing the ballast, but each type has to be carefully designed to each type of ballast, or a group of similar ballasts, thereby severely limiting their usefulness as a general replacement product.

A number of solutions describing LED-based light sources for replacement of fluorescent tubes are known in the art. However, the major drawbacks of such solutions are that they require the ballast to be bypassed or completely removed, because LED tubes do not need a high voltage, which is needed to ionize the gasses inside the respective gas-filled fluorescent tubes before sustaining a continuous lighting. An example of a fuse for bypassing the ballast in a traditional fluorescent light tube fixture for substituting a fluorescent light tube with an LED tube is disclosed in the Australian patent application, AU 2013 101266 A4.

The previously known solutions will not be able to work properly with respect to desired dimming of the light intensity.

SUMMARY OF THE INVENTION

It is thus an objective of the present invention to provide an LED tube which can enhance the possibilities for controlling the light intensity.

According to the invention, in a first aspect, the objective is achieved through a lighting device, said lighting device comprising:

- a light fixture;

- at least one LED tube, said LED tube comprising

- a tubular housing having two ends and a platform disposed between said two ends,

- an array of LEDs fixed on said platform, - a bi-pin comprising two electrical terminals extending from each end of said tubular housing, and

- an LED driver circuit fixed inside said tubular housing for the provision of electrical power to the LED array; and

- an LED fuse adapted to be inserted in a socket in a light fixture;

wherein the LED fuse comprises

- circuitry adapted to vary the current in the light fixture; and

- in connection with the LED fuse a receiving unit adapted to receive a signal input for the circuitry adapted to vary the current and feeding this signal to the circuitry;

the circuitry further being adapted to adapt the current in a predetermined manner in accordance with the signal input received by the receiving unit.

The LED driver circuit may have two identical fluorescent tube emulation circuits and a power conversion unit, each of said fluorescent tube emulation circuits being associated with one of the bi-pins, to which one bi-pin said fluorescent emulation circuit is electrically connected.

The lighting device may have a sensor integrated with the fuse unit, e.g. a PI R or a LUX sensor, or such sensor may be remotely located and communicating wired or wireless with the fuse unit.

By a lighting device, in this context is meant a device adapted to include one or more light sources, where light sources may be incandescent lamps (light bulbs), fluorescent tubes, LED tubes, Halogen spots or the like. Thus, a lighting device can also be called a lamp. A lighting device may comprise a body/fixture with a slot for each light source and a socket (or two sockets in the case of fluorescent tubes or LED tubes) for electrically connecting the light source to the lighting device. In a second aspect of the invention, the objective is achieved through a lighting system comprising at least one lighting device, where at least some of said lighting devices comprises:

- a light fixture;

- at least one LED tube, said LED tube comprising

- a tubular housing having two ends and a platform disposed between said two ends, - an array of LEDs fixed on said platform,

- a bi-pin comprising two electrical terminals extending from each end of said tubular housing, and

- an LED fuse adapted to be inserted in a socket in a light fixture;

wherein the LED fuse comprises

- circuitry adapted to vary the current in the light fixture; and

the circuitry further being adapted to adapt the current in a predetermined manner in accordance with the signal input received by the receiving unit. The at least one lighting device may have a sensor integrated with the fuse unit, e.g. a PIR or a LUX sensor, or such sensor may be remotely located and communicating wired or wireless with the fuse unit.

Preferably, the lighting system comprises a transmitting unit for transmitting a control signal to the receiving unit of the lighting device . In such embodiment a manual control of the light intensity may be obtained, e.g. any desired level of dimming may be achieved.

Combinations of the mentioned signal providers, i.e. sensor and remote transmitter, may be an option as well.

In third aspect of the invention the objective is achieved through an LED fuse unit for a lighting device, the LED fuse unit comprising:

- an connection part adapted to be inserted in a socket in a light fixture;

- a circuitry adapted to vary the current in the light fixture; and

- a receiving unit adapted to receive a signal input for the circuitry and feeding this signal to the circuitry;

the circuitry further being adapted to adapt the current in a predetermined manner in accordance with the signal input received by the receiving unit. Such fuse unit may be installed in any existing light fixture with a socket for a glow switch and provide the added effect of increased controllability of the lighting device.

The fuse unit may have a sensor integrated with it, e.g. a PI R or a LUX sensor, or such sensor may be remotely located and communicating wired or wireless with the fuse unit.

When using a transmitting unit for transmitting a control signal to the receiving unit a manual control of the light intensity may be obtained, e.g. any desired level of dimming may be achieved.

Combinations of the mentioned signal providers, i.e. sensor and remote transmitter, may be an option as well. In a fourth aspect of the invention, the objects of the invention are further achieved, by a method of replacing a fluorescent tube in a light fixture of a lighting device (of a lighting system comprising at least one lighting device), with an LED tube, the method comprising,

- removing the fluorescent tube from the tube sockets of the light fixture

- bypassing the ballast adapted to a fluorescent tube

- removing the glow switch fuse adapted to a fluorescent tube from the light fixture;

- inserting a LED fuse unit in the glow switch socket of the light fixture, the LED fuse unit comprising:

- an connection part adapted to be inserted in a socket in a light fixture;

- a circuitry adapted to vary the current in the light fixture; and

- the circuitry further being adapted to adapt the current in a predetermined manner in accordance with the signal input received by the receiving unit;

- inserting a LED tube in the tube sockets of the light fixture.

In embodiments of the method, the LED fuse unit may be of the type according to any of the embodiments described in connection with the second aspect of the invention. BREIF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings. In the following, preferred embodiments of the invention are explained in more detail with reference to the drawings, wherein:

Fig. 1 shows an embodiment of an LED tube with a tubular housing according to the present invention;

Fig. 2 shows a cross section of the tubular housing shown in Fig. 1 ;

Fig. 3 shows a schematic overview of the main components of an embodiment of an LED tube;

Fig. 4 shows in more detail the main components of the electronic driver circuit Fig. 5A in a side view, shows a first embodiment of an LED fuse unit according to the invention;

Fig. 5B in a perspective view, shows the LED fuse unit of Fig. 5A;

Fig. 6 shows a second embodiment of an LED fuse unit according to the invention;

Fig. 7 shows a third embodiment of an LED fuse unit according to the invention; Fig. 8 schematically shows the coupling of the LED fuse unit to the lighting device in a light fixture;

Fig. 9 schematically shows the components of an embodiment of an LED fuse unit; and

Fig. 10 shows various signal providers for the LED fuse unit according to embodiments of the invention.

DETAILED DESCRIPTION The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully con- vey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout. Like elements will thus not be described in detail with respect to the description of each figure.

Fig. 1 shows an embodiment of an LED tube 2 according to the present invention. The LED tube has a tubular housing 4, two ends 6, and a platform 8 disposed between said two ends 6, an array 10 of LEDs 11 fixed on said platform 8, and a bi-pin 12 comprising two electrical terminals 14 extending from each end 6 of said tubular housing 4. The tubular housing 4 generally has the outer form and dimensions of a typical fluorescent light tube.

Fig. 2 shows a cross section of the tubular housing 4 shown in Fig. 1. The illustrated tubular housing 4, preferably metallic in material, also serves as a heat sink with a toothed profile 16 to increase the heat dispersion. Other types of projections can be formed on the outer surface of the tubular housing 4 for improved heat dispersion.

The platform 8, which supports the array 10 of LEDs 11 , preferably comprises a printed circuit board, PCB, on which the LEDs may be mounted. The LED array 10 is covered by a light permeable cover 18, which may be formed from glass or Plexiglass. Also visible in Fig. 2 is an enclosure 20 for an LED driver/LED driver circuit (not shown in Fig. 2).

Fig. 3 shows a schematic overview of the main components of an embodiment of an LED tube 2 for use with the invention. The illustrated LED tube 2 comprises a driver circuit/LED driver circuit/electronic driver circuit 28 arranged inside the tubular housing 4 of the LED tube 2for the provision of electrical power to a load, e.g. the LED array 1 1. The LED driver circuit 28 may be arranged in an enclosure 20 below the platform 8, as described in connection with Fig. 2 above. Both ends 6 of the illustrated LED tube 2 are galvanically isolated, thereby eliminating the risk of electric shock during installation of the LED tube 2 into a live socket.

From Fig. 4 the main components of the electronic driver circuit 28 appear. The main components are here a power conversion circuit 32, and at each end of this, and connected to the electrical terminals 14, a fluorescent tube emulation circuit 30. From Fig. 5A and 5B a first embodiment of an LED fuse unit 34 according to the invention appears. The LED fuse unit 34 is adapted to fit into a fuse socket of a light fixture (not shown), such as a glow switch socket, as commonly used for fluorescent lighting devices. Traditional light fixtures for fluorescent light tubes comprises tube sockets for connecting one or more fluorescent light tubes, a ballast and a fuse, which is adapted to currents and voltages used in connection with flourescent light. The LED fuse unit 34 according to the invention replaces the traditional fuse of the light fixture, when the fluorescent light tubes are replaced with LED tubes, and the ballast adapted to fluorescent light tubes is bypassed.

Fig. 5A shows the LED fuse unit 34 in side view, and Fig. 5B shows the LED fuse unit 34 in a perspective view. The LED fuse unit 34 comprises a connection part 35, with a set of electrical terminals 37, and a housing 36. The connection part 35 with the set of electrical terminals 37 is configured for cooperating with a fuse socket of a light fixture, such as a glow switch socket. In this embodiment, the connection part 35 is integrated with the housing 36, and forms the lower portion thereof. The set of electrical terminals 37 is adapted for contacting cooperating electrical terminals provided in the fuse socket (not shown) of the light fixture. The inside of the housing may comprise various control equipment for controlling light emission from LED tubes mounted in the light fixture, as will be explained in further detail below.

A second embodiment of the fuse unit 34 according to the invention is shown in Fig. 6, where a portion of 36' of the housing 36 above the socket has been expanded to accommodate various components if more space is needed. In this embodiment, housing 36 thus comprises the connection part 35 with a set of electrical terminals 37, and the expanded portion 36'. The above mentioned components may be distributed in the expanded portion 36' or in both the expanded portion 36' and the connection part 35.

In Fig. 7 a third embodiment of the fuse unit 34 according to the invention is shown, where the fuse unit 34 has been divided into a connection part 35 and a housing part 36", and where the connection part 35 and the housing part 36" are formed in separate cabinets or housings. The connection part 35 in this embodiment forms a simple electrical plug 38, which is adapted to connect with the fuse socket terminals , and preferably only comprises the electrical terminals 37 configured for connection to the corresponding terminals of the fuse socket of the light fixture. An electrical wire connection 40 is provided between the plug 38 and the housing 36". In all of the embodiments the housing 36, 36', 36" defines a component enclosure 42 accommodating the various components of the LED fuse unit 34.

Fig. 8, in schematic form, shows the LED fuse unit 34, when installed in a light fixture, as intended in serial connection with the LED tube 2.

The main components of the LED fuse unit 34, which are integrated in the housing 36, are illustrated schematically in Fig. 9. The components comprises a receiving unit in the form of an interface 44 for a signal input and control of the LED fuse unit. The interface 44 is configured for receiving and feeding a control signal to a dimmer 46, and further on to a switch 48 (or switches) that will control the current fed to the LED tube 2. Thus, the interface, dimmer and/or switch may form parts of a circuitry adapted to vary the current in the light fixture.

Fig. 10A-C, in schematic form, illustrates various examples of input signal providers for communicating with the LED fuse unit 34 in order to control the LED tube or tubes in the light fixture. In one embodiment, illustrated in Fig. 10B, the interface 44 comprises, or is connected to, a passive infrared sensor, PIR sensor 52. Thereby, if a person enters a room with a LED fuse unit installed in a light fixture, the LED fuse unit 34 may turn the light on. In another embodiment, illustrated in Fig. 10C, the interface 44 comprises, or is connected to, a LUX sensor 54. Thereby, the LED fuse unit may turn the LED tubes in the light fixture on and off dependent on a measured ambient light intensity. The PIR sensor 52 or the LUX sensor 54 may provide an input that mainly will serve the purpose of switching on the lighting device. In a further embodiment, and as illustrated in Fig. 10A, the interface 44 comprises, or is connected to, a signal receiver 50 for receiving a control signal from a remotely arranged control unit (not shown), preferably wireless, may be an option. Through the remote control, a user may dim the light, turn the light on or off. In further embodiments, the interface may comprise of be connected to a combination of a signal receiver 50 and sensors, such as the above mentioned PIR and LUX sensors 52, 54. The lighting device described above may form part of a system comprising a plurality of lighting devices (at least one), e.g. is at a manufacturing site or a warehouse or the like. In this case, traditional fluorescent tube lighting devices, may be converted into LED tube lighting devices by bypassing the ballast of each traditional lighting device, replacing the fuse adapted for fluorescent tubes with a LED fuse unit as described above, and then replacing the fluorescent tubes with LED tubes. All of - or individual or groups of - lighting devices in the system may be controlled by a control unit.

The control unit may therefore be any of the following: sensors, remote control units, timers, etc. The control unit may be wired or wirelessly connected with the fuse. By means of the control unit the fuse according to the invention may be used to turn on/off the LED lighting device and may further be used for dimming of the light when a remote control is used.

LIST OF REFERENCE NUMBERS

2 LED tube,

4 tubular housing,

6 end of the tubular housing,

8 platform,

10 Array of LEDs

11 LED,

12 bi-pins,

14 electrical terminals/terminals of bi-pin,

16 toothed profile of heat sink,

18 light permeable cover,

20 enclosure for LED driver,

28 LED driver circuit,

30 fluorescent emulation circuit,

32 power conversion unit,

34 fuse unit,

35 connection part of fuse unit

36 housing of fuse unit,

36' expanded portion of housing of fuse unit

36" separate housing of fuse unit

38 plug/electrical plug,

40 wire/electrical wire connection,

42 component enclosure,

44 interface

46 dimmer,

48 switch,

50 wireless receiver

52 PIR sensor

54 LUX sensor

56 ballast

Claims

1. A lighting device comprising:

-a light fixture;

-an LED tube comprising

- a tubular housing

- two ends

- a platform disposed between said two ends,

- an array of LEDs fixed on said platform,

- a bi-pin comprising two electrical terminals extending from each end of said tubular housing,

- an LED fuse unit adapted to be inserted in a glow switch socket in the light fixture,

the LED fuse unit comprising

- circuitry adapted to vary the current in the light fixture, and

- in connection with the LED fuse unit, a receiving unit adapted to receive a signal input for the circuitry adapted to vary the current and feeding this signal to the circuitry,

2. A lighting device according to claim 1 , further comprising a transmitting unit for transmitting a control signal to the receiving unit.

3. A lighting device according to claim 1 , where a sensor is provided for providing a signal input to the receiving unit.

A lighting device according to claim 3, where the sensor is a PI R sensor or a LUX sensor.

5. An LED fuse unit for an LED lighting device, the LED fuse unit comprising:

- a connection part adapted to be inserted in a glow switch socket in a light fixture; - the LED fuse unit comprising circuitry adapted to vary the current in the light fixture; and

6. An LED fuse unit according to claim 5, where a signal receiving unit is provided for providing a signal input to the receiving unit.

7. An LED fuse unit according to claim 6, where the signal receiving unit is a PIR sensor or a LUX sensor, or a wireless receiving unit.

8. A method of replacing a fluorescent tube in a light fixture of a lighting device of a lighting system comprising at least one lighting device, with an LED tube, the method comprising,

removing the fluorescent tube from the tube sockets of the light fixture bypassing the ballast adapted to a fluorescent tube

removing the glow switch fuse adapted to a fluorescent tube from the light fixture;

inserting a LED fuse unit in the glow switch socket of the light fixture, the LED fuse unit comprising:

an connection part adapted to be inserted in a socket in a light fixture; a circuitry adapted to vary the current in the light fixture; and

the circuitry further being adapted to adapt the current in a predetermined manner in accordance with the signal input received by the receiving unit;

inserting a LED tube in the tube sockets of the light fixture.