GB2546977A

GB2546977A - A lamp unit

Info

Publication number: GB2546977A
Application number: GB1601708.9A
Authority: GB
Inventors: Lloyd Matthew; Cuthbert Richard
Original assignee: Global Design Solutions Ltd
Current assignee: Global Design Solutions Ltd
Priority date: 2016-01-29
Filing date: 2016-01-29
Publication date: 2017-08-09
Also published as: GB201601708D0

Abstract

It is desirable to replace standard tungsten filament lamp units with LEDs but to retain the ability to reproduce the lighting effects achievable by the former, especially at the lower end of the brightness range. To achieve this a lamp unit 10 is provided comprising at least two LEDs, a processor for controlling a behavioural characteristic of each one of the at least two LEDs independently of each of the other at least two LEDs, and a memory means for storing a set of instructions for the processor to use to thereby independently control the behavioural characteristic of each of the at least two LEDs. The instructions may include a look-up table or an algorithm using which the lamp unit may be arranged to mimic the dimming behaviour of an incandescent lamp.

Description

A lamp unit

The present invention relates generally to a lamp unit and a method of operating a lamp unit and finds particular, although not exclusive, utility in the lighting of auditoria.

The use of LEDs to replace tungsten filament light bulbs is well known and popular since it results in lower power usage and longer life of the light units. However, it is often perceived that LEDs do not dim well with regard to their stability, often flickering noticeably. Further, the transition from bright to zero brightness towards the bottom few percent of brightness is often uneven and LEDs may often suddenly jump to zero from a brightness of a few percent rather than transitioning smoothly. Furthermore, whereas tungsten filament bulbs tend to produce a warmer colour (lower colour temperature) towards the lower end of their brightness range, LEDs do not.

In auditoria, such as theatres, where many tens, if not hundreds of lighting units are often provided there is a great financial saving to be made by replacing tungsten filament bulbs with LEDs. The present “house lights” have the desirable qualities of being dimmable in unison, smoothly transitioning to zero without undesirably large steps, and producing a warmer colour at their lower brightness levels.

It is desirable to be able to replace these tungsten filament bulbs with LEDs having the same qualities.

Accordingly, in a first aspect the invention provides a lamp unit comprising at least two LEDs, a processor for controlling a behavioural characteristic of each one of the at least two LEDs independently of each of the other at least two LEDs, and a memory means for storing a set of instructions for the processor to use to thereby independently control the behavioural characteristic of each of the at least two LEDs.

The processor may be programmable. The two LEDS may be operated such that they have a different brightness from one another, or such that one is not lit, at any given point in time. The two LEDs may have different colour qualities in that they are able to provide different colour ranges. By combining the light provided by the two LEDs, as they are controlled independently, differing lighting effects are producible.

The set of instructions may be in the form of a look-up table. The processor may determine a value from the incoming duty cycle, in the power supplied to the lamp unit, to input into the look-up table to provide values for the duty cycles which it is to provide to the two LEDs. The look-up table may provide only one value which may then be further processed to provide a different value and a consequent duty cycle for each of the LEDs. Alternatively, there may be more than one look-up table, such that there is a look-up table for each TED. Another possibility is that the set of instructions is in the form of one or more algorithms which may provide one or more values for one or more consequent duty cycles such that a duty cycle may be provided to each LED.

Other formats for the set of instructions are contemplated.

The memory may store more than one set of instructions.

The behavioural characteristic may be the brightness of each one of the at least two LEDs. The brightness is typically determined by the duty cycle supplied to the LED in question.

The behavioural characteristic may be the colour of each one of the at least two LEDs. In this regard, the colour may be the colour temperature. This may also be typically determined by the duty cycle supplied to the LED in question.

The lamp unit may further comprise a receiver for receiving signals which affects the operation of the processor and its subsequent control of each one of the at least two LEDs.

For instance, the signal may instruct the lamp unit to override the set of instructions and power-off the LED. Other instructions may be passed in this way to the lamp unit.

The receiver may be configured to receive electromagnetic signals. For example, the receiver may be configured to receive infra-red signals.

The receiver may be arranged to receive signals which include a set of instructions for storing in the memory means. This may be a new, additional set of instructions, or a replacement set.

The receiver may be arranged to receive signals which selects a set of instructions stored in the memory means for the processor to use. In this respect, the signal may direct the processor as to which set of instructions to employ, in situations where the memory stores more than one set of instructions.

The lamp unit may further comprise a transmitter for transmitting signals carrying information related to the performance and/or status of the lamp unit. For instance, the lamp unit may be able to report any one or more of the following: its serial number, how many hours the LED has worked, the current temperature of the unit, which set(s) of instructions it is presently using, its firmware version, and its date of manufacture. In this respect, the processor is programmable to perform such actions.

The transmitter may be configured to transmit electromagnetic signals, for example, infra-red signals.

The at least two LEDs may be arranged on a stalk extending from the processor. The stalk may be connected directly to the processor. The stalk may comprise a printed circuit board. The stalk may be soldered to a printed circuit board which comprises the processor.

The lamp unit may comprise two sets of the at least two LEDs, the two sets set arranged on either side of the stalk. The LEDs may be arranged at the end of the stalk.

The lamp unit may have more than one stalk each with at least two LEDs arranged thereon. For instance, the unit may have three stalks. The three stalks may be arranged substantially symmetrically around the interior of the unit.

The lamp unit may operate on a DC voltage of less than 50Y. Alternatively, or additionally, the lamp unit may operate on an AC voltage of greater than 100Y.

One of the at least two LEDs may produce white light and the other of the at least two LEDs may produce amber light.

In a second aspect, the invention provides an array of lamp units according to the first aspect, wherein the lamp units are configured such that the brightness of their output is substantially synchronised in the range of 0 to 2% brightness. In this regard, the lamp units may be configured to reach zero brightness simultaneously such that they dim at their “bottom end” in approximate synchronisation in a smooth manner without jumps in their brightness.

In a third aspect, the invention provides a method of operating a lamp unit according to the first aspect, comprising the steps of providing the lamp unit, connecting an electricity supply, and operating the processor using the set of instructions stored in the memory means such that the behavioural characteristic of each of the at least two LEDs is controlled independently.

The method may further comprise the step of sending a signal to the lamp unit to thereby change the operation of the processor. For instance, the additional step of selecting a different set of instructions for the processor to use to operate/control the LEDs may be included.

The method may further comprise the step of sending a signal to the lamp unit to thereby store a set of instructions in the memory means. This may be effected by the processor being capable of “reading” the signal and following an instruction within the signal, and/or basing its operation on pre-set instructions programmed into the processor, or stored in a memory, to be followed on receipt of the necessary signal, to store the set of instructions in the memory means.

The method may further comprise the step of sending a signal to the lamp unit to thereby select a set of instructions stored in the memory means for the processor to use in operating the at least two LEDs. This may be effected by the processor being capable of “reading” the signal and following an instruction within the signal, and/or basing its operation on pre-set instructions programmed into the processor, or stored in a memory, to be followed on receipt of the necessary signal, to use a defined set of instructions stored in the memory means for operating the LEDs.

One of the at least two LEDs may produce white light and the other of the at least two LEDs may produce amber light. In this respect, white light may have a colour temperature greater than 3000K, and the amber light may have a colour temperature less than 3000K. Alternatively, the white light may have a colour temperature greater than 2000K, and the amber light may have a colour temperature less than 2000K. The amber light may emit light with a wavelength of approximately 600nm.

The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

Figure 1 is an elevational view of a lamp unit;

Figure 2 is a plan view of the TED support member within the lamp unit; and

Figure 3 is a graph of the brightness of two LEDs versus duty cycle.

The present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to be an embodiment of the invention. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein.

It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

Similarly, it is to be noticed that the term “connected”, used in the description, should not be interpreted as being restricted to direct connections only. Thus, the scope of the expression “a device A connected to a device B” should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. “Connected” may mean that two or more elements are either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other. For instance, wireless connectivity is contemplated.

Reference throughout this specification to “an embodiment” or “an aspect” means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, or “in an aspect” in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any embodiment or aspect of the invention may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects.

Similarly, it should be appreciated that in the description various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the description provided herein, numerous specific details are set forth. Flowever, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The use of the term “at least one” may mean only one in certain circumstances.

The principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features of the invention. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching of the invention, the invention being limited only by the terms of the appended claims.

The lamp unit 10 depicted in Figure 1 is similar to a typical candle shape light fitting comprising an elongate glass dome 20 attached to a base 30 with a bayonet fitting 40 at its base for connection into a standard light fitting socket.

The base 30 may include a heat sink in the form of fins (not shown) arranged around its outer circumference. Within the base 30 a PCB 60 is provided which comprises a processor, memory store, receiver and transmitter (not shown).

The PCB 60 is substantially rectangular in shape with an extension portion 65 in the form of a smaller rectangular arranged at one end thereof. This extension portion 65 extends through a slot in the base of an LED support member 66.

From the I .I 'D support member 66 three stalks 70 extend into the glass dome 20. The LEDs (not shown) are arranged at the far ends of each of the stalks.

The stalks 70 are shown indicatively only. They may take the form of “T” shape members with the LEDs (not shown) arranged horizontally side-by-side on the upper cross-bar of the “T” shape. Other shapes of stalk and arrangement of LEDs are contemplated, such as a stalk without an upper cross-bar and the LEDs being arranged in a vertical line thereon.

The base 30 may be filled with potting compound.

It is to be understood that there may be more or less than three stalks 70. It is to be understood that fittings other than a bayonet fitting 40 may be provided, such as screw-fit, GU10 etc.

With regard to Figure 2, the LED support member 66 is seen to be approximately triangular in plan with a slot 67 at its centre through which the extension portion 65 extends.

The three stalks 70 extend upwardly from the LED support member 66 with a cross-bar 80 at the top of each on which are shown two LEDs 90 on each side thereof. In some instances more than two LEDs 90 may be arranged such as three LEDs comprising two amber LEDs and one white LED arranged on each side of each stalk 70. The amber LEDs may be arranged on either side of the white LED.

The extension portion is soldered 68 to the LED support member 66. The LED support member 66 may be a PCB itself and include electrically conducting tracks within it, or on it which carry the electricity from the PCB 60 to the LEDs 90. In this way, no filament-like wires are necessary leading to a more robust light fitting. In this regard, the term filament-like refers to wires having a diameter less then 1mm.

In use the differing colour LEDs may be operated at differing duty cycles at the same time as each other to produce the desired light qualities. With reference to Figure 3 a graph of the duty cycles (X-axis 110) versus the brightness (Y-axis 120) of two LEDs is shown. In this example, the line referenced “130” refers to the amber LED and the line referenced “140” refers to the white LED, although other colours are contemplated.

The X-axis is referring to the duty cycle of the pulse width modulated incoming current to the lamp unit and not to the duty cycle sent on to the LEDs hy the processor.

It can be seen that with an incoming duty cycle for the lamp unit being zero, the processor provides no power to the LEDs such that their brightness is zero. As the incoming duty cycle increases, the brightness of the amber LED is increased to a maximum 135 at approximately 50% of the incoming duty cycle current. Thereafter, as the incoming duty cycle current from 5050 to 100% the brightness of the amber LED is reduced. The increase and decreases in brightness of the amber LED is not showm as being linear. Rather, the increase and decreases is non-linear and similar to being exponential. However, it is to be understood that other rates of increase and decrease are contemplated and that the rates of increase and decrease may be different.

The other line 140 shows how with an increase in incoming duty cycle current to the lamp unit the brightness of the white LED increases exponentially from zero to a maximum. Again, it is to be understood that other rates of increase are contemplated and although not shown, the brightness may also decrease with an increase in incoming duty cycle current.

The processor provides an output duty cycle current to the two LEDs based on the set of instructions it is using. The set of instructions may be stored in a memory means (not shown). The memory means may be updated, or the processor directed to sue a particular set of instructions by means of an infra-red transmission from, for example, a hand-held remote control.

Other means for communicating with the lamp units are contemplated such as by means of DMX, PWM etc...

With regard to Figure 3, it is seen how in the first half of the Y-axis as the incoming duty cycle increases the overall light mix will start at zero brightness, then move to a dim warm glow leading to a bright warm glow before then becoming more white and less of a warm colour in the second half of the Y-axis. In this respect a warm glow may have a colour temperature of below 3000K, and the less warm brighter white light may have a colour temperature of above 3000K.

With the processor following a different set of instructions different overall light mixes are possible.

Claims

1. A lamp unit comprising at least two LEDs, a processor for controlling a behavioural characteristic of each one of the at least two LEDs independently of each of the other at least two LEDs, and a memory means for storing a set of instructions for the processor to use to thereby independently control the behavioural characteristic of each of the at least two LEDs.

2. The lamp unit according to claim 1, wherein the behavioural characteristic is the brightness of each one of the at least two LEDs.

3. The lamp unit according to either one of claims 1 and 2, wherein the behavioural characteristic is the colour of each one of the at least two LEDs.

4. The lamp unit according to any preceding claim, further comprising a receiver for receiving signals which affects the operation of the processor and its subsequent control of each one of the at least two LEDs.

5. The lamp unit according to claim 4, wherein the receiver is configured to receive electromagnetic signals.

6. The lamp unit according to claim 5, wherein the receiver is configured to receive infra-red signals.

7. The lamp unit according to any one of claims 4 to 6, wherein the receiver is arranged to receive signals which include a set of instructions for storing in the memory means.

8. The lamp unit according to any one of claims 4 to 7, wherein the receiver is arranged to receive signals which selects a set of instructions stored in the memory means for the processor to use.

9. The lamp unit according to any preceding claim, further comprising a transmitter for transmitting signals carrying information related to the performance and/or status of the lamp unit.

10. The lamp unit according to claim 9, wherein the transmitter is configured to transmit electromagnetic signals.

11. The lamp unit according to claim 10, wherein the transmitter is configured to transmit infra-red signals.

12. The lamp unit according to any preceding claim, wherein the at least two LEDs are arranged on a stalk extending from the processor.

13. The lamp unit according to claim 12, comprising two sets of the at least two LEDs, the two sets set arranged on either side of the stalk.

14. The lamp unit according to either one of claims 12 and 13, having more than one stalk each with at least two LEDs arranged thereon.

15. The lamp unit according to any preceding claim, operating on a DC voltage of less than 50V.

16. The lamp unit according to any preceding claim, operating on an AC voltage of greater than 100V.

17. The lamp unit according to any preceding claim, wherein one of the at least two LEDs produces white light and the other of the at least two LEDs produces amber light.

18. An array of lamp units according to any preceding claim, wherein the lamp units are configured such that the brightness of their output is synchronised in the range of 0 to 2% brightness.

19. A method of operating a lamp unit according to any one of claims 1 to 17, comprising the steps of providing the lamp unit, connecting an electricity supply, and operating the processor using the set of instructions stored in the memory means such that the behavioural characteristic of each of the at least two LEDs is controlled independently.

20. The method according to claim 19, when dependent either directly or indirectly on claim 4, further comprising the step of sending a signal to the lamp unit to thereby change the operation of the processor.

21. The method according to claim 20, when dependent either directly or indirectly on claim 7, further comprising the step of sending a signal to the lamp unit to thereby store a set of instructions in the memory means.

22. The method according to either one of claims 20 and 21, when dependent either directly or indirectly on claim 8, further comprising the step of sending a signal to the lamp unit to thereby select a set of instructions stored in the memory means for the processor to use in operating the at least two LEDs.

23. The method according to any one of claims 19 to 22, wherein one of the at least two LEDs produces white light and the other of the at least two LEDs produces amber light.

24. A lamp unit substantially as hereinbefore described with reference to Figures 1 and 2.