CROSS-REFERENCE TO PRIOR APPLICATIONS

This application is the U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2019/073069, filed on Aug. 29, 2019, which claims the benefit of European Patent Application No. 18192259.2, filed on Sep. 3, 2018. These applications are hereby incorporated by reference herein.

FIELD OF THE INVENTION

The invention relates to a light device.

The invention further relates to a method of activating at least one light source.

The invention also relates to a computer program product enabling a computer system to perform such a method.

BACKGROUND OF THE INVENTION

The default behavior of a typical connected light device, when it is supplied with power, is that it will start up at its default factory configured power on color (typically 2700K white light). The Zigbee Lighting & Occupancy Device Specification version 1.0 specifies a StartUpOnOff attribute that defines the desired startup behavior of a light device when it is supplied with power. When the StartUpOnOff attribute is set to the value 0xff, the light source(s) of the light device are activated (turned on) if they were on before the power was last turned off and not activated if they were off before the power was last turned off.

The advantage of this solution is that a user will not need to turn the light off or on again after a power outage occurs, which is especially beneficial in regions with an instable power grid, e.g. India.

However, a drawback of this solution is that when a user first switches the light device into standby mode, e.g. using his mobile device or a dedicated remote control, when he no longer needs the light provided by the light device and then uses a legacy wall switch to cut the power to the light device before he leaves, when he returns and uses the legacy wall switch again, the light does not turn on. Instead of using his mobile device or dedicated remote control to activate the light source, the user may end up flicking the wall switch several times until he realizes his mistake or concludes that the light device is broken.

U.S. Pat. No. 5,212,478 A discloses a dynamic system by which an electrically-powered load recovers from a power outage after power is restored.

SUMMARY OF THE INVENTION

It is a first object of the invention to provide a light device, which is able to react better to power outages.

It is a second object of the invention to provide a method of activating at least one light source, which can be used to react better to power outages.

In a first aspect of the invention, the light device comprises at least one light source, a memory and at least one controller configured to, upon being powered on, read a value from said memory, said value depending on how long said light device was continuously powered on before said light device was last powered off, determine from said value whether said light device was continuously powered on for more than a predetermined period before said light device was last powered off, and activate said at least one light source in dependence on said determination. Said at least one controller is preferably configured to activate said at least one light source upon determining that said light device was continuously powered on for less than said predetermined period before said light device was last powered off.

The inventor has recognized that it is beneficial to detect whether a user is flicking a light switch, i.e. cutting power and immediately restoring power, and activating a light source connected to the light switch when this behavior is detected. This is more likely to be the behavior that the user is expecting and informs the user that the light device is not broken. The inventor has further recognized that whether a user is flicking a light switch can be detected by determining whether said light device was continuously powered on for more than a predetermined period before said light device was last powered off, as the light device will only be powered on briefly if a user is flicking a light switch a couple of times and when power is restored after a power outage, another power outage will normally not occur again immediately.

For example, a light device has at least two modes, goes to a predetermined setting upon being powered on in a first mode and normally goes to a last known state upon being powered on in a second mode. The light device implements the invention by not always going to the last known state in the second mode, but instead activating its light source if the previous power cycle was short, e.g. due to a wall switch double toggle.

Said at least one controller may be configured to transmit an information signal upon activating said at least one light source, said information signal indicating that a fast power cycle has occurred. This may be used as an additional warning to the user or to someone that may be near the user.

Said at least one controller may be configured to control said at least one light source to assume a state active just before said light device was last powered off upon determining that said light device was powered on for more than said predetermined perioded before said light device was last powered off. The risk that a user does not realize that he needs to use his mobile device or a dedicated remote control to activate the light and control the light device is typically somewhat larger if the light device is configured to assume a state active just before said light device was last powered off than if the light device is configured to always turn on in an OFF state.

Said at least one controller may be configured to assume said state if said light device has been configured with a preference to turn on in a last known state. Although certain types of light devices may always turn on in a last known state, the startup behavior of more advanced types of light device may be configurable, e.g. by the user.

Said at least one controller may be configured to read a configuration value of a Zigbee StartUpOnOff attribute and determine that said light device has been configured with a preference to turn on in a last known state if said configuration value equals 0xff. The use of Zigbee is advantageous, because many existing light devices use wireless communication that conforms to this standard.

Said at least one controller may be configured to receive a configuration input indicating that said light device is to be configured with a preference to turn on in a last known state and configure said light device with a preference to turn on in a last known state in dependence on said configuration input. This allows the user to configure the startup behavior of the light device.

Said value may depend on whether said light device was continuously powered on for more than a predetermined period before said light device was last powered off. This avoids the need to frequently write the elapsed time in the current power cycle to a non-volatile memory. For example, said at least one controller may be configured to set said value to a first value upon determining that a timer has elapsed and control said at least one light source to assume a state active just before said light device was last powered off if said value read from said memory equals said first value.

Said at least one controller may be configured to receive a configuration input indicating a time period and configure said predetermined period to equal said indicated time period. The specified time period may be chosen such that it is shorter than the duration of short power outages that may occur to prevent that short power outages cause the light(s) to turn on.

In a second aspect of the invention, the method comprises, upon said light device being powered on, reading a value from a memory of a light device, said value depending on how long said light device was continuously powered on before said light device was last powered off, determining from said value whether said light device was continuously powered on for more than a predetermined period before said light device was last powered off, and activating said at least one light source in dependence on said determination. Said method may be performed by software running on a programmable device. This software may be provided as a computer program product.

Said at least one light source may be activated upon determining that said light device was continuously powered on for less than said predetermined period before said light device was last powered off.

Said method may further comprise controlling said at least one light source to assume a state active just before said light device was last powered off upon determining that said light device was continuously powered on for more than said predetermined perioded before said light device was last powered off.

Said state may be assumed if said light device has been configured with a preference to turn on in a last known state.

Moreover, a computer program for carrying out the methods described herein, as well as a non-transitory computer readable storage-medium storing the computer program are provided. A computer program may, for example, be downloaded by or uploaded to an existing device or be stored upon manufacturing of these systems.

A non-transitory computer-readable storage medium stores at least one software code portion, the software code portion, when executed or processed by a computer, being configured to perform executable operations comprising, upon said light device being powered on: reading a value from a memory of a light device, said value depending on how long said light device was continuously powered on before said light device was last powered off, determining from said value whether said light device was continuously powered on for more than a predetermined period before said light device was last powered off, and activating said at least one light source in dependence on said determination.

As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a device, a method or a computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit”, “module” or “system.” Functions described in this disclosure may be implemented as an algorithm executed by a processor/microprocessor of a computer. Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied, e.g., stored, thereon.

Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a computer readable storage medium may include, but are not limited to, the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of the present invention, a computer readable storage medium may be any tangible medium that can contain, or store, a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber, cable, RF, etc., or any suitable combination of the foregoing. Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java™, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor, in particular a microprocessor or a central processing unit (CPU), of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer, other programmable data processing apparatus, or other devices create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of devices, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

