A method of messaging with light is implemented by a light fixture. The method includes: timing and recording a switch-on period, and recording an operation mode of the light fixture during receipt of the electrical power; and operating in a messaging mode the next time the light fixture receives electrical power upon determining that the recorded operation mode is a lighting mode and that the recorded switch-on period is within a predetermined range of time period. In the messaging mode, the light fixture controls a light emitting device to send a binary message by operating in a sequence composed at least of a first brightness state and/or a second brightness state.

A method of messaging with light is implemented by a light fixture. The method includes: timing and recording a switch-on period, and recording an operation mode of the light fixture during receipt of the electrical power; and operating in a messaging mode the next time the light fixture receives electrical power upon determining that the recorded operation mode is a lighting mode and that the recorded switch-on period is within a predetermined range of time period. In the messaging mode, the light fixture controls a light emitting device to send a binary message by operating in a sequence composed at least of a first brightness state and/or a second brightness state.

Systems an methods are provided that disclose providing a positioning service for devices based on light received from one or more light sources. This light based positioning service uses light information transmitted by each light source to determine the position of the device. The positioning information can include three dimension position information in a building that can then be used to deliver services and information to a mobile device. The content delivered to a mobile device can include multimedia, text, audio, and/or pictorial information. The positioning information along with other location or positioning information can be used in providing augmented reality or location aware services. The light sources can be independent beacons that broadcast information in visible light at a rate that is undetectable by the human eye. Content can be retrieved from a server over a communications connection.

Systems an methods are provided that disclose providing a positioning service for devices based on light received from one or more light sources. This light based positioning service uses light information transmitted by each light source to determine the position of the device. The positioning information can include three dimension position information in a building that can then be used to deliver services and information to a mobile device. The content delivered to a mobile device can include multimedia, text, audio, and/or pictorial information. The positioning information along with other location or positioning information can be used in providing augmented reality or location aware services. The light sources can be independent beacons that broadcast information in visible light at a rate that is undetectable by the human eye. Content can be retrieved from a server over a communications connection.

A current mirror circuit that amplifies a reference current generated by a current source at a first magnification to supply a mirror current to a load circuit. The current mirror circuit includes a first transistor and a second transistor that share a power supply, and a drain potential mirror unit that amplifies the reference current at a second magnification to generate a first current, that amplifies a generated first current at a third magnification to generate a second current, and that supplies a predetermined potential determined based on the second current to a drain of the second transistor. The mirror current is supplied from the second transistor to the load circuit based on a potential of a gate of the first transistor determined based on the reference current.

A current mirror circuit that amplifies a reference current generated by a current source at a first magnification to supply a mirror current to a load circuit. The current mirror circuit includes a first transistor and a second transistor that share a power supply, and a drain potential mirror unit that amplifies the reference current at a second magnification to generate a first current, that amplifies a generated first current at a third magnification to generate a second current, and that supplies a predetermined potential determined based on the second current to a drain of the second transistor. The mirror current is supplied from the second transistor to the load circuit based on a potential of a gate of the first transistor determined based on the reference current.

The present disclosure provides an optical module, including: an optical sub-module and a first housing; where a first sub-surface of the optical sub-module is provided with a first boss, and the first housing is provided with a first opening corresponding to the first boss. The improved structure of the optical module can greatly increase heat conduction efficiency of the optical module.

The present disclosure provides an optical module, including: an optical sub-module and a first housing; where a first sub-surface of the optical sub-module is provided with a first boss, and the first housing is provided with a first opening corresponding to the first boss. The improved structure of the optical module can greatly increase heat conduction efficiency of the optical module.

An optical signal receiving device includes a receiver configured to receive an optical signal on which modulation has been performed by an optical signal transmission device, a convertor configured to convert the optical signal received by the receiver to a digital signal by sampling an intensity of the optical signal, and a processor coupled to the converter and configured to determine, based on a frequency distribution of the intensity of the optical signal indicated by the digital signal converted by the converter, a modulation scheme of the modulation performed by the optical signal transmission device.

An optical signal receiving device includes a receiver configured to receive an optical signal on which modulation has been performed by an optical signal transmission device, a convertor configured to convert the optical signal received by the receiver to a digital signal by sampling an intensity of the optical signal, and a processor coupled to the converter and configured to determine, based on a frequency distribution of the intensity of the optical signal indicated by the digital signal converted by the converter, a modulation scheme of the modulation performed by the optical signal transmission device.