Abstract: An imaging apparatus includes: a plurality of pixels each of which includes a conversion element and a first transistor of which one of a source and a drain is connected to the conversion element; and a second transistor which is shared by the plurality of pixels and has a gate connected respectively to the other of the source and the drain of the first transistor of each of the plurality of pixels. At least one among the gate, a source, a drain and a channel portion of the second transistor is formed to be extended over the plurality of pixels, and the conversion element is arranged over the first and second transistors.

Abstract: In a night vision arrangement for a motor vehicle a camera is provided which captures an image which is subsequently displayed on a display arrangement which may be a head-up display arrangement. The camera directs light on to a beam deflector which may be constituted by a mirror which deflects the beam so that it passes along a neck on to a sensor. The camera may relatively easily be mounted in position in a motor vehicle.

Abstract: An electronic device capable of detecting ultraviolent radiation and a method thereof are provided. The device includes a camera, a voltage-sensitive optical medium, a control switch, and a processor. When the electronic device enters an ultraviolent radiation detecting mode, the camera captures a first image. The processor controls the control switch to create an electrical potential across the optical medium and cause it to become darker after the camera captures the first image. The camera captures a second image after the control switch has allowed an electrical potential for a first preset time interval. The processor acquires reads the respective brightness of the first image and the second image, determines any difference, and determines and outputs the level of intensity of the ultraviolent radiation intensity by reference to a table of differences.

Abstract: Embodiments provide methods for monitoring a plurality of worksites at a facility, the methods including transporting a central monitoring station package to the facility, seating a transport container, stationing worksite monitoring equipment packages at the worksites, connecting communication links from the worksite monitoring equipment packages to central monitoring station equipment, transmitting remote transmissions from worksite monitoring equipment packages to central monitoring station equipment, displaying worksite monitoring information for a monitoring technician, and responding when remote monitoring information received from a worksite meets a response threshold criteria.

Abstract: A digital X-ray capture device that uses an image array camera to capture a digital image of a standard X-ray film. The X ray-film is placed on a tray within a housing. An array of LED lights located under the tray illuminate the film. In the preferred embodiment the illuminated image of the X-ray bounces off a forty-five degree angle mirror and enters the image array camera. The digital image can then be downloaded to a standard computer. Custom software allows the user to manipulate the image as needed. The entire capture process takes only two seconds. A patients information can be added to the boarder of the captured image. The captured image can be sent via email to any other computer.

Abstract: An apparatus for detecting and viewing an invisible indicia includes an illumination source for illuminating the invisible indicia with radiation of a first wavelength; a sensor array for detecting emitted light from the invisible indicia at a second wavelength; a filter between the sensor and the invisible indicia for eliminating reflected radiation at the first wavelength; a lens for focusing an image of the invisible indicia on the sensor array; a video display for displaying the image of the invisible indicia; a spacer for spacing the sensor array at a fixed distance from the invisible indicia; and a gain control for adjusting sensitivity of the sensor array.

Abstract: A paper remote controller system capable of registering and controlling a plurality of apparatuses with an easy manipulation and superior in convenience and flexibility is provided. The input system for an apparatus using a dot pattern comprises a reading unit for reading out a dot pattern formed based on a predetermined rule on a medium surface, a converting unit for analyzing a dot pattern from image information of the dot pattern read out by the reading unit and converting the dot pattern into a dot code corresponding to the dot pattern, an infrared code table for registering one or a plurality of infrared codes that are related with the dot code, and a control unit for causing an infrared code read out from the infrared code table to be irradiated from an infrared emission unit to a control-subject apparatus.

Abstract: A night vision system has a night vision illuminator, an imaging apparatus, and a first light conditioning structure. The night vision illuminator is configured for illuminating a space with near-infrared (NIR) light that is linearly polarized in a direction substantially parallel with a first polarization axis. The imaging apparatus is configured for creating an electrical representation of an image defined by NIR light received thereby. A field of view of the imaging apparatus includes at least a portion of the space illuminated with the NIR light of the night vision illuminator. The first light conditioning structure is configured for linearly polarizing in a direction substantially non-parallel with respect to the first polarization axis the NIR light received by the imaging apparatus.

Abstract: A system and method for situational awareness and target cueing for use in military applications is disclosed. In extreme low light situations where the LLL sensor cannot provide SA information, the system allocates thermal information to the green SA channel to maintain the supply of contextual information to the user and thus situational awareness (SA) never drops below the native resolution of the thermal sensor. This improved SA capability, surpasses any existing LLL sensor technology in a single channel (stand-alone) application in overcast star light and below conditions.

Abstract: According to one implementation of the present invention, there is provided a radiation image capturing system. The system includes, a radiation source; a plurality of radiation image capturing devices; and a console. The console manages which of the radiation image capturing devices is in a state where image capturing is possible. The console registers image capturing order information including information of which radiation image capturing device is used in the image capturing, or obtains the registered image capturing order information. When there is a radiation image capturing device in a state where image capturing is possible, regardless of a predetermined order, the console displays the icon corresponding to the image capturing order information including information of the radiation image capturing device in a manner different from the other icons.

Abstract: A pupil detection device includes a camera, a light source disposed at the camera, an optical system, and an image processing system, which are disposed so that the examinee's face is irradiated with the light from the light source from the camera, and a face image including a pupil is formed in the camera. The light source includes a first light source, having a first wavelength that makes a bright pupil image by reflection in the examinee's pupil, and a second light source having a second wavelength that makes a dark pupil image by reflection in the examinee's pupil, but otherwise exhibiting the same illumination effect as the first light source. The camera includes a first image data acquisition system using the first illumination light source, and a second image data acquisition system using the second illumination light source.

Abstract: A mosaic image is input that is made up of a visible light component image in which mainly a visible light component has been captured and a non-visible light component image in which mainly a non-visible light component has been captured, and spectrally corrected images are generated in which spectral characteristics of each pixel have been corrected. Contrast enhancement processing is then performed on one of the spectrally corrected images that has been generated and that includes the non-visible light component, and a non-visible light component image is generated in which contrast has been enhanced. A spectral correction portion generates the spectrally corrected images by performing a matrix computation that uses a spectral characteristics correction matrix M that is generated using information on ideal spectral characteristics.

Abstract: An imaging apparatus with adjustable imaging plane, the apparatus having mechanical, electronic or optical devices to adjust the position and the orientation of the imaging plane, which successively captures a plurality of images while adjusting the imaging plane, and a method to integrate the captured images to a single high-resolution image by exploration of the mutual information not available in a single image, such as the sub-pixel observations due to the spatial misalignment, thus achieving an image resolution higher than the sensor resolution.

Abstract: A hybrid image of a scene is formed by obtaining a visible light image and a quantum entanglement image of the scene. Light intensity channel information is extracted from the visible light image of the scene, and a ghost image of the scene is constructed by cross-correlating the extracted light intensity channel information with the quantum entanglement image. The visible light image is thereafter fused with the ghost image so as to form a hybrid image of the scene.

Abstract: In the method disclosed, three or more infrared images of a body having concealed objects are acquired, each image resulting in a response of a detector having a spectral sensitivity in the infrared that is analogous to one of the spectral sensitivities of the color response of the human eye, and each image corresponding to a different spectral sensitivity. At least the center of the spectral sensitivity corresponding to the Green response at the human eye is selected to allow increasing the detected radiation difference between the concealed object and the body. The responses of the detector to each of the three or more images are utilized to provide RGB signals to a display device. The color image displayed in the display device allows identifying the concealed object.

Abstract: An improved lighting technique via a lighting technique utilizing a light source invisible to the subject is provided herein. The improved lighting technique capability blends image data from an image detector sensitive to visible light with corresponding image data from an image detector sensitive to light not visible to humans to create an improved image.

Abstract: A radiation image capturing system includes at least one image capturing apparatus including a radiation detector, at least one image capturing apparatus including a stimulable phosphor panel for generating radiation image information, which is readable by an image reading apparatus, and at least one control device for controlling at least the image capturing apparatus and the image reading apparatus based on image capturing instruction information supplied from an external source. The control device includes a change setting unit for changing settings of the image capturing instruction information depending on whether the image capturing apparatus and the image reading apparatus are usable or not, and a controller for controlling the image capturing apparatus and the image reading apparatus based on the changed settings of the image capturing instruction information.

Abstract: In order to provide a photoelectric conversion apparatus, which is an apparatus excellent in reading speed, high S/N, high tone level, and low cost, the photoelectric conversion apparatus has a photoelectric conversion circuit section comprising a plurality of photoelectric conversion elements, switching elements, matrix signal wires, and gate drive wires arranged on a same substrate in order to output parallel signals, a driving circuit section for applying a driving signal to the gate drive wire, and a reading circuit section for converting the parallel signals transferred through the matrix signal wires to serial signals to output them, wherein the reading circuit section comprises at least one analog operational amplifier connected with each of the matrix signal wires, transfer switches for transferring output signals from the respective matrix signal wires, output through each amplifier, reading capacitors, and reading switches for successively reading the signals out of the reading capacitors in the for

Abstract: A method of assessing the integrity of a rock mass, the method including receiving a thermal assessment of the integrity of a rock mass, receiving an acoustic assessment of the integrity of a rock mass and correlating the thermal- and acoustic assessments to obtain a combined assessment of the integrity of a rock mass. The invention also covers an assessment apparatus for assessing the integrity of a rock mass, which includes acoustic assessment means operable to provide an acoustic assessment of the integrity of a rock mass, thermal assessment means operable to provide a thermal assessment of the integrity of a rock mass and correlation means for correlating the acoustic assessment of the integrity of a rock mass with the thermal assessment of the integrity of a rock mass.

Abstract: The present invention concerns a method and camera for obtaining a high-contrast image of a predetermined target present in an area under observation. The method involves obtaining an in-band image of the observation area including the target using a filter whose bands are aligned with selected characteristic wavelength bands of the target and an out-of-band image of the observation area excluding the target using the filter with its bands non-aligned with the selected characteristic wavelength bands of the target. Processing of the in-band and out-of-band images results in a high-contrast image highlighting the presence of the target in the observation area and thereby allowing its detection and monitoring.

Abstract: An object of examination is irradiated with an electromagnetic wave including a frequency component from 30 GHz to 30 THz and a Fourier transform image of the transmitted or reflected electromagnetic wave from the object of examination is obtained. The obtained Fourier transform image is subjected to a spatial frequency filtering processing. This method can visualize only the part to be visualized in an imaging operation using a terahertz wave.

Abstract: Systems and methods that may be employed to visually locate and/or track objects equipped with active RFID tags. The disclosed systems and methods may employ an articulated camera/s, such as closed circuit television (“CCTV”) or other suitable type of articulated camera/s, that is equipped with an antenna array.

Abstract: A video and data capturing system and method includes a mobile unit having an image sensor and motion sensing equipment connected to a microprocessor. The mobile unit is installed in an object for detecting visual images and motion data associated with the object. The mobile unit communicates with a base unit capable of analyzing the image and motion data and correcting the image data so it is level with the horizon. A foot unit may be used in conjunction with the mobile unit for detection of an athlete's foot acceleration for determining when the athlete's foot comes in contact with the ground. A field unit may be used in conjunction with the mobile unit and foot unit to determine the location of the foot unit on a playing surface to assist in determining whether an athlete is in or out of bounds, or their location on the playing surface.

Abstract: A night vision coloring system may color a scene by extracting the spectral signature of each area in a scene and matching the extracted signature with a predetermined database signature and associated color. The system may comprise a temporal or spatial filtering element that may typically allow the capturing of an image reflection through a plurality of spectral bands, thereby extracting the spectral signature of each area in the image. The color associated with the matched database signature may be used to color each area comprising the image.

Abstract: Visible light image capturing is performed at appropriate timing that corresponds to the action of a subject. An image capturing system includes: an infrared light image capturing section that successively captures a plurality of infrared light images of a subject, using infrared light; a timing predicting section that predicts timing at which the subject included in the plurality of infrared light images matches a predetermined condition, based on timing at which each of the plurality of infrared light images is captured and image content of the plurality of infrared light images; and a visible light image capturing section that captures a visible light image by using visible light at the timing predicted by the timing predicting section.

Abstract: An imaging apparatus includes an electron emission array having electron sources arranged in matrix form, a photoelectric conversion film opposed to the electron emission array, and a control and drive circuit configured to select one or more horizontal scan lines in a given video signal output period and to cause the electron sources included in the selected one or more horizontal scan lines to emit electrons toward the photoelectric conversion film, wherein the control and drive circuit is further configured to cause the electron sources included in the selected one or more horizontal scan lines to emit electrons toward the photoelectric conversion film in any one or more blanking periods excluding both a blanking period immediately following the given video signal output period and a blanking period immediately preceding a next video signal output period in which the one or more horizontal scan lines will be selected next time.

Abstract: A device for capturing a silhouette consisting of a transparent wall, a vision device to capture at least one image of the wall and a processing unit connected to the vision device which analyses the captured images and detects the silhouette of the individual passing between the transparent wall and the vision device. More than one pattern is positioned on the transparent wall and the patterns exhibit a contrast with the transparent wall.

Abstract: Systems and methods are disclosed herein to provide filtering techniques for image processing applications. For example, in accordance with an embodiment of the present invention, a Median-X filtering algorithm is disclosed that may be used for various infrared image processing applications.

Abstract: A radiation image capturing apparatus includes: a radiation detector for detecting charge information; an analog multiplexer for passing an analog charge information signal read out from each pixel of the radiation detector, alternately in a first order and a second order opposite to the first order; an analog signal amplifier for amplifying the analog charge information signal; an analog/digital converter for converting the analog charge information signal to a corresponding digital charge information signal; and a signal correcting unit for using one of a first digital charge information signal corresponding to the analog charge information signal that has passed through the analog multiplexer in the first order and a second digital charge information signal corresponding to the analog charge information signal that has passed through the analog multiplexer in the second order, to correct the other of the first digital charge information signal and the second digital charge information signal.

Abstract: Provided are a system and method for image sharpening is provided that involves capturing an image, and then decomposing the image into a plurality of image-representation components, such as RGB components for example. Each image-representation component is transformed to obtain an unsharpened multi-resolution representation for each image-representation component. A multi-resolution representation includes a plurality of transformation level representations. Sharpness information is transported from an unsharpened transformation level representation of a first one of the image-representation components to a transformation level representation of an unsharpened multi-resolution representation of a second one of the image-representation components to create a sharpened multi-resolution representation of the second one of the image-representation components. The sharpened multi-resolution representation of the second one of the image-representation components is then transformed to obtain a sharpened image.

Abstract: A displacement estimation method is disclosed which includes: a signal capturing step for capturing a signal; a displacement estimation step for calculating a displacement based on a state change of the signal; and an output step for outputting the displacement, in which the displacement estimation step includes one or more of the steps of (A) consistency check to determine whether the state change of the signal is consistent with the waveform of the signal; (B) period prediction and compensation to count in the present period according to a proportional length of a previous period; and (C) adaptive threshold update to adjust the definition of the state change corresponding to the amplitude of the signal.

Abstract: An imaging system, particularly a thermal imager, has a detector operating in at least two sensitivity modes. The detector is read on a pixel-by-pixel basis in each of at least two modes and output therefrom is substantially simultaneously displayed so that a wide range of thermal sensitivities are simultaneously displayed. The detector is, preferably, read out at maximum and minimum sensitivity levels at least half the field rate and, advantageously, at the field rate of a display. In a preferred embodiment, color is added to the normally provided gray scale output from the detector ranging from black for the coolest object through white and yellow to red for the hottest object.

Abstract: Focusing systems and methods for remotely controlling a focal position of an objective lens assembly in a night vision optical device are provided. The focusing system includes a focusing device and a focus selector. The focusing device includes an objective lens assembly positioned among two or more focus positions from an imaging array and a focus controller, coupled to the objective lens assembly, configured to translate the objective lens assembly relative to the imaging array among the two or more focus positions. The focus selector is remote from the focusing device and is configured to wirelessly transmit a selected focus position to the focus controller. The objective lens assembly is translated to one of the two or more focus positions in response to the selected focus position transmitted by the focus selector.

Abstract: The present invention advantageously provides a means by which the privacy zone on a PTZ camera can be maintained so that an object in the camera's sight is always masked or covered. An algorithm which remembers the defined privacy zones as an area in space marked by four rays touching the four corners of the marked zone and having absolute Pan, Tilt angular coordinates is presented. The privacy zone is initially defined by a rectangle on the screen with known pixel co-ordinates which are translated into angular coordinates. Then, when the camera moves and prepares to display a new screen, the privacy zone is superimposed on the object to be masked. Locating the object and displaying its privacy zone is done by translating the absolute angular coordinates of the original privacy zone into pixel coordinates. Additionally, multiple privacy zones can be displayed on one camera screen.

Abstract: Method and apparatus for the correction of a non-uniform sensitivity of detector elements in thermographic cameras in which background frames of an internal reference are recorded in shutter phases when the beam path of the thermographic camera is closed, the variations between the background frames of the shutter phases are logged, and an updated background frame is generated and used for the correction of at least one image frame, characterized in that the updated background frame is generated from at least one newly recorded background frame and a background frame to be updated in that the data of every pixel of the newly recorded background frame are multiplied by a first factor and are added to the data of every pixel of the background frame to be updated which are multiplied by a second factor, wherein the first factor is a value between zero and one, and the second factor is the difference between one and the first factor, so that the data of every pixel of the updated background frame are in the form

Abstract: A system including an image acquisition subsystem receiving electromagnetic radiation from a body, a spectral decomposition subsystem separating the received electromagnetic radiation into at least a number of predetermined spectral components, each one component from the number of predetermined components corresponding to a response to a non-visible analogue to a visible spectrum representation of the predetermined spectral components, a wavelength of the received electromagnetic radiation being in a non-visible range, and an analysis subsystem receiving the at least the number of predetermined components, identifying at least one region in an image obtained from at least one the number of predetermined components and providing a color image, the color image obtained from the visible spectrum representation of the non-visible analogue; the at least one region of the color image enabling detection of a concealed object.

Abstract: Image sequences are accessed, the sequences each taken, from a different perspective, of a portion of a radiation region defined by projected electromagnetic radiation. The image sequences each include a projection image taken during an emitting period in which the projected electromagnetic radiation is emitted, the projection image being of ambient electromagnetic radiation and of an object within the portion being illuminated with the projected electromagnetic radiation, and an ambient image taken during an extinguishing period in which the projected electromagnetic radiation is extinguished, the ambient image being of the ambient electromagnetic radiation. A position of the object using the projection images and the ambient images is determined, an application is controlled based on the determined position.

Abstract: The invention provides an imaging apparatus (10) for obtaining an image (40) of a fluorescent pattern (32) under ambient light, such as a fluorescent barcode or a fingerprint dyed with a fluorescent marker. The apparatus includes a synchronous shutter imaging device (12) having an image recording sensor and a shutter, a first pulsed light source (18) which emits a pulse of light having an excitation wavelength of the fluorescent pattern, an optical filter (14) which prevents light having the excitation wavelength from reaching the image recording sensor of the synchronous shutter imaging device, and a synchronisation control (22) which synchronises the shutter and the pulsed light source. The synchronisation of the shutter and pulse, so that the shutter opens during the pulse, and the provision of the optical filter allow a low intensity light source to be used and an image to be obtained under ambient light conditions.

Abstract: A device for imaging an object by electromagnetic high frequency radiation including at least one detector for electromagnetic high frequency radiation and at least one imaging device for generating a focus. To provide a device for and a method of imaging an object by electromagnetic high frequency radiation, which makes it possible to detect even a rapidly moving object with a high level of resolution, it is proposed that the device has at least one controllable element for changing the beam direction, which is so adapted that the focus of the imaging device is movable.

Abstract: A user portable viewing device (D) includes a plurality of non-coaxially aligned sensors (26 and 32) for sensing a scene (74). A processing element (P) combines electronic images into a single electronic image. A display (24) displaying the combined electronic image is adaptable for mounting in an optical axis (A1) including an eye (20) of the user (U) and an input end (28) of the first sensor 26 for direct view. In a second embodiment, a system for fusing images comprises sensors (52 and 56) for generating sets of image data. An information processor (P) receives and samples the sets of image data to generate sample data for computing a fused image array. A display (24) receives the fused image array and displays a fused colorized image generated from the fused image array.

Abstract: A video system includes first and second sensors generating respective primary and secondary video sequences of images of a scene. The first sensor is responsive to thermal infrared (IR) energy, and the second sensor is responsive to shorter-wavelength optical energy in a range from visible to near-IR wavelengths. The sensors are temporally and spatially registered. A motion estimation module generates an estimated motion vector field from the secondary video sequence, and a motion-based image processor applies one or more image-enhancement operations to the primary video sequence based on the estimated motion vector field.

Abstract: A millimeter wave imaging apparatus includes: an imaging device having a plurality of millimeter wave sensors that are arranged in a planar manner and receive millimeter waves radiated from a subject to detect signal levels thereof; an image data generation device that generates image data of the subject based on an output from each of the millimeter wave sensors constituting the imaging device; and a case that has a placement surface on which the subject can be placed and which permits transmission of the millimeter waves. The imaging device is arranged below the placement surface of the case, so that the millimeter waves, which are radiated from a bottom part of the subject placed on the placement surface of the case, are received by the plurality of millimeter wave sensors.

Abstract: A process is described comprising the preparation of subject objects with special colors that are invisible to the human eye, use of paired cameras to capture the subject object(s), use of pattern recognition software to merge the images. The merged image when accompanied by with behaviors will allow the creation of an OOP object that will facilitate automatic creation of animation-like special effects and CGI-like special effects.

Abstract: A method, a controller and a vehicle for performing agricultural operations on a field with parallel arranged rows having ends. The operations are performed at positions related to the positions of the rows under control of the controller, based upon stored information about the orientation of the rows, stored information about a distance between adjacent rows, a distance signal related to a distance traveled by the vehicle and a direction signal related to the heading of the vehicle. The invention is particularly suited for providing dams to prevent water from a head ditch to enter into pre-selected, dry furrows on a field with an irrigation arrangement with raised rows and lower furrows between the rows, or dams matching up with adjacent raised rows so that water runs down each furrow.

Abstract: A concealed object detection system using pre-engineered and pre-manufactured components to effectively control the deployment surroundings and provide a known environment in which the equipment can operate. The system provides inherent background/peripheral motion and optical clutter mitigation by virtue of its booth-like design. The system can additionally include x-ray baggage machines, iris scanners, biometrics, finger readers, palm readers, metal detectors, backscatter x-ray, nuclear quadrupole resonance, explosives-trace detectors (“sniffers”), and access control cards.

Abstract: Images of foreground objects in a scene are generated by causing electromagnetic radiation to be emitted having a first spectral power distribution from a surface of a first foreground object, which is adjacent or at least partially obscured by a second foreground object. A first image of both of the first and second foreground objects is acquired whilst the first foreground object emits electromagnetic radiation with the first spectral power distribution. A second image of the first and second foreground objects is acquired whilst the first foreground object is not emitting electromagnetic radiation or is emitting electromagnetic radiation with a second spectral power distribution which is different to the first spectral power distribution. An alpha matte of the first and second foreground objects is generated based on a comparison of the first image and second image.

Abstract: A mark which at least reflects or radiates invisible light of predetermined wavelength other than visible light is added in a space of the real world. A camera apparatus comprises image capturing means for capturing a real image in which an invisible-light image may be discriminating. An image processing apparatus, comprises: mark discriminating means for discriminating at least one condition of a position of image of mark in the captured real image, a orientation of the mark, and a distance from the mark to the image capturing means, and overlaying condition determining means for determining, in correspondence with the discriminated condition, a overlaying condition which is at least one of an overlaying position which is a position of the image of the virtual object overlaid on the captured real image in the real image, an orientation of the virtual object which the age of the virtual object indicates, and a distance from a view point of viewer, of the image of the virtual object.

Abstract: An illuminator comprises a thermal imager for generating a thermal image of a warm object, and a device for converting the thermal image to a visible light image and projecting and superimposing the visible light image back onto the object to illuminate the object with light that conforms to the outline of the object so that the object is easier to see in darkness.

Abstract: The present application is directed to a radiant energy emitting device, comprising (1) a targeting means operationally configured to repeatedly identify a target surface area; (2) an image recording means for recording one or more images of a target surface area; and (3) a powered energy source housed within the device operationally configured to emit energy; wherein the device is operationally configured to concentrate energy emitted from the energy source out through an aperture of the device toward the target surface area.

Abstract: A light guiding device is operable to receive incident light emitted by a light source through a capture surface. The received light exits the light guiding device through an exit surface provided adjacent to and aligned with an aperture of light receiver. In this manner, light from the light source can be inserted into the receiver where it may be combined with additional incident light captured by the receiver. The light source might be a projector and the light projected may correspond to operational data relating to the operation of the receiver or images corresponding to data captured by a further receiver device operating with a different form of sensor or in a different region of the spectrum. In order to improve the composite image observed by a user of the light receiving device, the operation of the light source can be controlled to vary the intensity of the light emitted. In one example, this variation can be in response to the ambient light level, as sensed by a suitable sensor.