Method and apparatus for controlling a light array

Abstract

A method and apparatus for controlling a light array include controlling an intensity modulated illumination of a randomised selection of a subset (e.g. 141-144) of an array 120 of light emitting elem

Description

FIELD OF THE INVENTION The invention relates to controlling a light array. In particular, the invention relates to controlling a light array for increased visibility. BACKGROUND TO THE INVENTION Lights are used as a warning or safety measure in many different situations. Lights may be used in stationary situations, for example, warning lights on towers, at barriers, as road markings, etc. Lights may also be used in moving situations, for example, on vehicles including road vehicles such as cars and motorcycles, watercraft, aircraft, etc. Vehicles such as motorcycles are particularly vulnerable to road accidents due to third parties not seeing the vehicle. Due to the size and manoeuvrability of a motorcycle, they often move through traffic quickly. Any early visibility to oncoming traffic and in vehicles’ rear or side view mirrors improves safety. Motorcyclists take many measures to make their vehicle as visible as possible to other road users. This includes using daytime running lights (DRL) that remain on when the engine is running, as well as many other types of auxiliary lights. Some motorcyclists use a headlamp modulator that oscillates between 20% and 100% intensity with full intensity 50% to 70% of the time. The preceding discussion of the background to the invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was part of the common general knowledge in the art as at the priority date of the application. SUMMARY OF THE INVENTION According to an aspect of the present invention there is provided a method for controlling a light array, comprising: repeatedly randomly selecting a subset of one or more light emitting elements in an array of light emitting elements over time; controlling a selected subset to control a variation of the illumination intensity of the selected light emitting elements in the subset with the variation being above a minimum intensity value that is greater than zero; and wherein the method maintains a light output of the array with no zero output of any light emitting elements whilst randomly varying the light output of the array. The method may include controlling a selected subset to vary between a minimum illumination and a higher intensity illumination, wherein the higher intensity illumination is greater than the illumination intensity of non-selected light emitting elements. The method may include maintaining the light output of the array above a minimum intensity value of the array by maintaining a set of the light emitting elements of the array that are not candidates for selecting as a subset and are kept at constant illumination. Repeatedly randomly selecting a subset may include one or more of the light emitting elements of a first subset being intensity varied for a time period until replaced by a second subset of randomly selected one or more light emitting elements. Controlling a selected subset to control a variation of the illumination intensity of the selected light emitting elements in the subset may include controlling at a constant increased illumination intensity for a period of time or a varying illumination intensity for a period of time. The random selection of a subset may include a varied number of light emitting elements in the subset. The varied number of light emitting elements in the subset may be one of: a randomly selected number, an increasing number, a decreasing number. The random selection of a subset may be selected from a restricted set of light emitting elements in the array. The restricted set of light emitting elements may be provided in a pattern in the array and / or in a different colour to the remainder of the array. The method may include merging the subset with a subsequent subset during a changeover period. The method may include configuring by a user one or more options for parameters of operation of the controller. The method may include activating the controlling of an intensity modulated illumination in response to an input or detected action. The frequency of modulation provided by the random selection may be in a frequency range perceptible by a human eye. According to an aspect of the present invention there is provided a light apparatus, comprising: a controller for controlling an intensity modulated illumination of an array of light emitting elements, wherein the controller is configured to: repeatedly randomly select a subset of one or more light emitting elements in the array of light emitting elements over time; and control a selected subset to control a variation of the illumination intensity of the selected light emitting elements in the subset with the variation being above a minimum intensity value that is greater than zero; wherein the controller maintains a light output of the array with no zero output of any light emitting elements whilst randomly varying the light output of the array. The light apparatus may be for a vehicle. The apparatus may include an activating component for activating the controlling of an intensity modulated illumination by the controller in response to a detected action. The apparatus may include an intensity modulation component for intensity modulation of each of a light emitting element in an array. The controller may be integrated into an accessory manager for controlling one or more lights each having an array of light emitting elements. Alternatively, the controller may be integrated into a light or a collection of lights each including an array of light emitting diodes. The method and apparatus include controlling an intensity modulated illumination of a randomised selection of a subset of an array of light emitting elements to vary the intensity of the light output of the subset between a lower percentage illumination intensity and an upper percentage illumination intensity with the lower percentage illumination intensity being greater than zero, with the remaining light emitting elements of the array remaining at a constant illuminated intensity. One or more of the light emitting elements of the subset may be intensity modulated for a time period until replaced by other randomly selected one or more light emitting elements. An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Figure 1 is a diagram of an example embodiment of a light array having an array of light emitting elements in which the described method of control may be implemented; Figure 2 is a flow diagram of an example embodiment of a method of control of a light array; Figure 3 is a schematic diagram of an example embodiment of a light apparatus; Figure 4 is a schematic diagram of a graph of light intensity against time as an illustration of the described light control; Figure 5A is a diagram of another example embodiment of a light array having an array of light emitting elements in which the described method of control may be implemented; and Figure 5B is a diagram of a further example of a light array having an array of light emitting elements in which the described method of control may be implemented; DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS A method of controlling a light array is described including illumination modulation. An apparatus for controlling a light apparatus is also described. The apparatus may be used to control existing lights having or forming an array of light emitting elements. Alternatively, the apparatus may be a complete arrangement include one or more lights forming an array of light emitting elements. The light emitting elements may be one or more light emitting diodes or equivalent light emitting sources. The light array and control apparatus may be used for stationary light situations or moving light situations, such as on a vehicle. A vehicle may be any vehicle, whether motorised or not, including but limited to motorcycles, cars, e-bikes, bicycles, etc. Portions of the following description use a vehicle light as an example embodiment. The method and apparatus for controlling a light array are configured to control an intensity modulated illumination of a randomised selection of a subset of the light emitting elements in the light array. The term randomised is intended to include a pseudo-randomised selection in which the selection is produced by a deterministic and repeatable process but appears to be random. A modulation of the light array is obtained whilst maintaining a minimum light intensity of the light emitting elements in the array so that the light array does not have any time in which there is no illumination at any of the light emitting elements. If a light has a time with no illumination, it flashes or strobes. Modulation as described herein is different to flashing or strobing in that there is always a minimum illumination. The illumination of the subset may be by an illumination for a defined selection period by a modulation (varying in non-zero illumination) whilst selected. The light array may have all the light emitting elements that are at a minimum illumination intensity, (for example, between 20 and 40% intensity), and may increase a selected subset to a higher illumination intensity (up to 100%) when selected. The selected subset may be illuminated in a constant illumination (for example, at 100%) or in a varying illumination (for example, between 40% and 100%). The selection of which of the subset are increased in illumination may be randomly selected. The randomised selection of the light emitting elements may change over time. In one embodiment, the randomised selection may change to a subsequent subset as a group at the end of a time period. The changeover may include a merging between the changeover of the subsets. In an alternative embodiment, each or a number of the selected light emitting elements in the subset may be replaced by other of the light emitting elements in the array. The replacement may also be on a randomised basis. The randomised selection of a subset may include a varied number of light emitting elements in the subset within a defined range. In one example, a subset of the light emitting elements may be randomly selected every time period (with the time period being either regular or varying) with the selected elements illuminated to a higher intensity for a set predefined time or until another subset is selected. In this example, the time period of selection provides the frequency of modulation. In another example, a subset of the light emitting elements may be randomly selected every time period (with the time period being either regular or varying) with the selected elements illuminated to a higher intensity for a variable time, for example, modulating with the time period. The variable time of illumination may be randomized. The frequency of intensity modulation provided by the subset selection may be in a frequency range perceptible by a human eye. This may be in a frequency range perceptible by a peripheral vision of a human eye whilst being imperceptible by a direct vision. The intensity modulation of the subset of light emitting elements improves the conspicuousness of the light, particularly in an observer’s peripheral vision where the vision is more sensitive to flickering light. The random nature prevents an observer from becoming accustomed to the flicker pattern and therefore catches the observer’s attention. The intensity modulated illumination varies the intensity of the light output of the subset of light emitting elements between a lower percentage illumination intensity and an upper percentage illumination intensity with the lower percentage illumination intensity being greater than zero. This provides a modulation of the light intensity without a flashing or strobe effect. In an embodiment in which there is a set of remaining light emitting elements of the array that are kept at a constant illuminated intensity, the constant illuminated intensity may be less than the upper percentage of the modulation so that the elements of the subset modulate to a brighter intensity compared to the remaining light emitting elements of the array. An increase in light intensity is easier to perceive by an eye or a camera, compared to a decrease in intensity. The subset may include more than one light emitting element and controlling the intensity modulated illumination of the subset of the light emitting elements may intensity modulate the light emitting elements within the subset. The subset may be selected to be an equal, majority, or minority proportion of the total number of the light emitting elements in the array. The portion may be selected to provide an equal or dominant number of constantly illuminated elements with a randomised flicker or sparkle effect provided by a lesser number of modulating elements. In other arrangements, the constantly illuminated elements may be a minority portion of the elements with a majority portion of the elements modulating. This may be applicable with high intensity lights. The number of light emitting elements within the subset may also be varied. This variation may increase or decrease the size of the subset over time, and this may be random or in response to a given situation. In one embodiment, the subset of light emitting elements may randomly switch on and then switch off after a defined time such that the frequency of modulation of intensity is provided by the combination of the subset of elements. The defined time may itself vary either randomly or, for example, becoming shorter (so that the randomisation increases in speed). Various embodiments of intensity variation of the light emitting elements in the subset may be provided. In some embodiments, the light emitting elements of a subset may modulate (by varying between bright and dim) once they are selected for a period of time before a next subset is randomly selected. The subset may modulate at a same frequency either at the same time or in a phased pattern whilst they are illuminated. In another embodiment, the light emitting elements of a subset may be divided into further subsets that modulate at different frequencies. In a further embodiment, the light emitting elements of a subset may change in frequency of modulation or flash, for example, by starting with a low frequency and building up to a higher frequency of modulation. The intensity modulation of the subset of the light emitting elements may be carried out in different phases of modulation within the subset. Different phases of modulation means that the light emitting elements of the subset are not all at their brightest at the same time. For example, if a first light emitting diode is modulated at a first frequency, a second light emitting diode may be modulated at the same frequency but delayed in modulation compared to the first. This may result in some elements being directly out of phase with the first element. This provides some elements as bright whilst others are dim, and ranges in between. The randomised selection may be selected from all light emitting elements in the array. Alternatively, the randomised selection may be selected from a restricted set of light emitting elements in the array. For example, the restricted set of light emitting elements may be provided in a pattern in the array. This may ensure that the modulating elements are distributed throughout the array. The restricted set of light emitting elements may be a different colour compared to the remainder of the array. For example, the remainder of the array may be white light with the restricted set being blue light which is the modulated intensity light. The number of the light emitting elements in the randomised subset may be varied. Referring to Figure 1, a diagram shows a light (100) having an array (120) of light emitting elements (121-132, 141-144). The array (120) may be of any configuration and a square configuration is shown in Figures 1 as an example. A subset (141-144) of the light emitting elements is randomly selected for intensity modulation at a given time as described herein. In this example, four of the 16 light emitting elements are shown as being in the subset (141-144). Referring to Figure 2, a flow diagram (200) shows an example embodiment of the described method. The method may be carried out by a controller of a light array. Steps of the method may be computer-implemented or electronically-implemented. The controller may be integrated into the light array or may be provided external to the light array. For example, an external controller may be part of an accessory management system of a vehicle or a light management system in other fields. The method may include (201) configuring parameters of the intensity modulation of a subset of the light emitting elements of a light. For example, a user may configure one or more of: a percentage range of the intensity modulation, an intensity of the remaining light emitting elements, a pattern or colour of a restricted set of elements that are to be modulated, and any other variable parameters. The method may activate (202) a modulating mode of the light. This may be activated in response to an activation input or event. The modulating mode may be activated by a purposeful input by a user for a period of time. The activation event may be a detected action carried out by a user. For example, in the context of a vehicle, the action may be applying the brakes, hooting the horn or otherwise carrying out some activity that suggests increased visibility is required. An activation event may be an external event that is sensed. Again in the context of a vehicle, the event may of a safety system or aid in a vehicle or external to a vehicle that may detect traffic or general risk profile in an area. The method randomly selects (203) a subset of light emitting elements of an array of the light and may vary the selection over time. The method (204) controls a variation of intensity illumination of the subset for or over a time period. The method may replace (205) one or more of the light emitting elements of the subset with other randomly selected light emitting elements. This may result in repeatedly randomly selecting a subset of one or more light emitting elements in an array of light emitting elements over time. The method maintains (206) a light output of the array above a minimum intensity value that is greater than zero whilst randomly varying the light output of the array. This results in a random modulation of the light emitted from the light array, where a modulation does not have time periods with no illumination, i.e. there is no “flash” or “strobe”. The method may deactivate (207) the modulating mode. This may be after a predefined time from the activating action or when purposefully deactivated by the user. The deactivation may be in response to a detected input or event. Referring to Figure 3, an example embodiment of a light apparatus (300) for control of a light array is shown. The apparatus (300) includes a light (100) as described in relation to Figure 1 as an example of a light (100) having an array (120) of light emitting elements (121-132, 141-144). A light emitting element (121-132, 141-144) may include one or more light emitting diodes. The apparatus (300) includes an intensity modulation component (370) for intensity modulation of each or a restricted number of the light emitting elements (121-132, 141-144) in the array (120). The intensity modulation component (370) may use pulse width modulation, current control, or digital control. The modulation control may vary the duration of a power pulse to make light emitting diodes appear dimmer or brighter as required. The intensity modulation is in essence the changing of the brightness of a light emitting element. The light emitting elements themselves may have small controllers that specifically control the current through an individual light emitting diode or a string of light emitting diodes. This is mainly done internally by a control loop that ultimately changes the pulse width to provide pulse width modulation. The internal light emitting diode controllers may have an input that reacts to a much slower pulse width (referred to as the outer loop control) that then forces the current control to behave as intended. Alternatively, instead of a pulse width modulation signal, the light emitting diodes may accept a digital data signal that instructs the brightness and colour, if relevant. The apparatus (300) includes a controller (350) for controlling an intensity modulated illumination of a randomised selection of a subset of the array (120) of light emitting elements to vary the intensity of the light output of the subset between a lower percentage illumination intensity and an upper percentage illumination intensity with the lower percentage illumination intensity being greater than zero, with the remaining light emitting elements of the array (120) remaining at a constant illuminated intensity. The controller (350) may include an intensity modulation signal transmitting component (360) for transmitting a signal to the intensity modulation component (370) for an identified light emitting element in the array (120). The controller (350) includes a random selection component (351) for randomised selection of a subset of the array of light emitting elements. The controller (350) may include a subset number varying component (352) for varying a number of light emitting elements in a subset. The controller (350) may include a time period varying component (353) for varying a time period for which a selected light emitting element is modulated. The controller (350) may include a set defining component (354) for defining a restricted set of light emitting elements in the array from which a subset is selected. The controller (350) may include various components for setting parameters of the controller (350). A user configuration component (358) may be provided for receiving user configuration of the parameter setting components to set one or more options for operation of the controller (350). The parameter setting components may include a modulated intensity defining component (356) for defining a lower percentage illumination intensity and an upper percentage illumination intensity for the subset and a constant intensity component (357) for defining the constant illuminated intensity for the remainder of the array. The parameter setting components may include a modulation frequency component (355) for defining the frequency of modulation. The controller (350) may include an activation component (359) for activating the controlling of an intensity modulated illumination by the controller (350) in response to a detected event or input. This may switch on and off the intensity modulation either intentionally by a user or in response to a sensed event. The controller (350) may be integrated into an accessory manager for controlling one or more lights (100) with each light (100) having an array (120) of light emitting elements. Alternatively, the controller (350) may be integrated into a light (100) or a collection of lights each including an array (120) of light emitting diodes. The controller (350) may include a microprocessor or microcontroller for algorithmically performing and executing the functions of components, which may be provided by hardware or by software units. The software units may be stored in a memory component and instructions may be provided to the processor to carry out the functionality of the described components. The controller (350) may receive inputs from external systems or devices, for example, a user mobile computing device such as a mobile phone. In the context of a light array of a vehicle, the controller (350) may include a microprocessor or a microcontroller that algorithmically performs the functions as described and may receive input from various sources ranging from user input to vehicle input and input from internal or external safety and / or information systems. Communications may be communicated over any of the standard automotive communications busses to wireless communications from within the vehicle. Referring to Figure 4, a schematic diagram (400) shows an example of a graph of illumination intensity (410) against time (420) of light emitting elements of an array. The diagram (400) is a simplified representation to illustrate the method of control of the light emitting elements of the array. A first subset (431) of the elements is randomly selected and the elements have an intensity modulated illumination in a range of modulation (440) for a time period (441). This may change to a second randomly selected subset (432) and then to a third randomly selected subset (433) and so on over time. The subsets (431, 432, 433) may have their element members varied so that they merge with different elements being randomly replace over time. The remainder (450) of the light emitting elements in the array have a constant illumination intensity. The constant illumination intensity may provide a minimum brightness so that there is always some level of illumination so that the overall light is not flashing. Flashing is deemed to be when a light switches off completely for a short period of time. The illumination intensity at any time may be equal to or higher than the minimum brightness. The range of total illumination intensity of the light array may be between 100% of the full intensity of all the elements and the minimum brightness. Finding the balance where the difference between a nominal “on” of the light array and the higher intensity modulation “sparkle” provided by the random subset is visible enough depends on the individual elements used. The human eye can detect flicker up to 90Hz, although reports are showing the possibility to distinguishing between steady and modulated light up to 500Hz. Therefore the frequency of intensity modulation of an element may have an upper limit of 100Hz. People are most sensitive to time-varying illumination in the range of 10-25Hz and a frequency range of 40-60Hz may make the modulation visible in the peripheral vision but may appear constant to direct vision. Therefore, a frequency may be selected as appropriate for the situation and context of the light array. The lower end of a frequency may is required to distinguish from a steady light state. Referring to Figures 5A and 5B, further example embodiments of possible forms of lights are shown. It will be appreciated that a large variety of formations may be used. In Figure 5A, alight (510) is formed of multiple clusters (511-516) of multiple light emitting diodes (LEDs). The clusters (511-516) are shown as a linear array. Each cluster (511-516) is shown with 9 LEDs. A subset of the clusters (511-516) may be randomly selected to have its LEDs intensity modulated. In this illustration, the third and fifth clusters (513, 515) are shown as being modulated. In Figure 5B, a light (520) is shown with an array of LEDs with a restricted set of the LEDs being able to be intensity modulated. The restricted set is shown within the boxes (541-546) in a pattern. Within the restricted set, a subset is shown (with solid fill) as randomly selected for intensity modulation at a given time. As an example, a light array may have X number of light emitting elements. All or a defined selection of the elements may be configured to “sparkle” due to intensity modulation. A randomised subset is selected to “sparkle” at any point in time. In one example, a single element may randomly “sparkle” due to intensity modulation. This may be used to create focus or awareness. For example this may be provided at a barrier or warning with lots of constant elements and a random intensity modulated one now and then sparkling. As an example of focus, a very few sparkles may keep an audience in anticipation until something happens, such as instructions appear. This may also use low frequency of intensity modulation where the frequency of one random sparkle to the next could be fractions of a Hertz and a specific element may never some on again. As a further example, a light array may have 100 light emitting elements and 50 of them may be selected to “sparkle” individually in different “random” sequenced times. A new element may come on every 0.1s and others may go off again somewhere in the sequence. A first element may not come on again before 10s have elapsed (0.1s x 50) and because the elements are varied randomly an element may not come back on again for a longer period of time. The foregoing description has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure. The language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims. Finally, throughout the specification and accompanying claims, unless the context requires otherwise, the word ‘comprise’ or variations such as ‘comprises’ or ‘comprising’ will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims

1. A method for controlling a light array, comprising:repeatedly randomly selecting a subset of one or more light emitting elements in an array of light emitting elements over time, wherein the random selection is selected from a restricted set of light emitting elements provided in a pattern in the light array;controlling a selected subset to control a variation of the illumination intensity of the selected light emitting elements in the subset with the variation being above a minimum intensity value that is greater than zero, including controlling the variation in a frequency range of 10 to 60 Hz; andwherein the method maintains a light output of the array with no zero output of any light emitting elements whilst randomly varying the light output of the array.

2. The method of claim 1, including controlling a selected subset to vary between a minimum illumination and a higher intensity illumination, wherein the higher intensity illumination is greater than the illumination intensity of non-selected light emitting elements.

3. The method of claim 1 or claim 2, including maintaining the light output of the array above a minimum intensity value of the array by maintaining a set of the light emitting elements of the array that are not candidates for selecting as a subset and are kept at constant illumination.

4. The method of any one of the preceding claims, wherein repeatedly randomly selecting a subset includes one or more of the light emitting elements of a first subset being intensity varied for a time period until replaced by a second subset of randomly selected one or more light emitting elements.

5. The method of any one of the preceding claims, wherein controlling a selected subset to control a variation of the illumination intensity of the selected light emitting elements in the subset includes controlling at a constant increased illumination intensity for a period of time or a varying illumination intensity for a period of time.

6. The method of any one of the preceding claims, wherein the random selection of a subset includes a varied number of light emitting elements in the subset.27 03 257. The method of claim 6, wherein the varied number of light emitting elements in the subset is one of: a randomly selected number, an increasing number, a decreasing number.

8. The method as claimed in any one of the preceding claims, wherein the restricted set 5 of light emitting elements is provided in a different colour to the remainder of the array.

9. The method as claimed in any one of the preceding claims, including merging the subset with a subsequent subset during a changeover period.10 10. The method as claimed in any one of the preceding claims, including configuring by auser one or more options for parameters of operation of the controller.

11. The method as claimed in any one of the preceding claims, wherein the frequency of modulation provided by the random selection is in a frequency range of 40-60 Hz perceptible 15 by a peripheral vision of a human eye.12 The method as claimed in any one of the preceding claims, including activating the controlling of an intensity modulated illumination in response to an input or detected action.20 13. A light apparatus, comprising:a controller for controlling an intensity modulated illumination of an array of light emitting elements, wherein the controller is configured to:repeatedly randomly select a subset of one or more light emitting elements in the array of light emitting elements over time, wherein the random selection is selected 25 from a restricted set of light emitting elements provided in a pattern in the light array;andcontrol a selected subset to control a variation of the illumination intensity of the selected light emitting elements in the subset with the variation being above a minimum intensity value that is greater than zero, including controlling the variation in 30 a frequency range of 10 to 60 Hz;wherein the controller maintains a light output of the array with no zero output of any light emitting elements whilst randomly varying the light output of the array.

14. The apparatus as claimed in claim 13, including an activating component for activating 35 the controlling of an intensity modulated illumination by the controller in response to a detected action.

15. The apparatus as claimed in claim 13 or claim 14, wherein the controller is integrated into an accessory manager for controlling one or more lights each having an array of light emitting elements.5 16. The apparatus as claimed in claim 13 or claim 14, wherein the controller is integratedinto a light or a collection of lights each including an array of light emitting diodes.

17. The apparatus as claimed in any one of claims 13 to 16, including:an intensity modulation component for intensity modulation of each of a light emitting element 10 in an array.

18. The apparatus as claimed in any one of claims 13 to 17, wherein the light apparatus is for a vehicle.27 03 25

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