Mobile communications device, controller, and method for controlling a mobile communications device

A mobile communications device. includes a communication unit for communicating with another device. The mobile communications device further has a communication unit for communicating with another device and at least one other component. A controller is connected to the communication unit and the component. The controller can control the component, during at least a part of time the communication unit is in a communicating mode, based on an operation of the communication unit.

FIELD OF THE INVENTION

This invention relates to a mobile communications device, to a controller, to a method for controlling a mobile communication device and to a kit of parts.

BACKGROUND OF THE INVENTION

Mobile communication devices, such as mobile telephones provided with a camera are known. The mobile telephone has a camera which can capture an image of an object and a flash-light which can generate a light flash in order illuminate the object when the camera generates the image. The mobile telephone further has a transceiver which can transmit and receive radio signals. The transceiver is connected to a power source, a 1000 mAh lithium-based chemical battery, which provides power to the transceiver.

However, a disadvantage is that the light source and the transceiver can not operate simultaneously. The transceiver includes a power amplifier which uses about 1 A of current during peak operation, whereas the light source typically draws a peak current of 1 A from the battery during the flash. In case the peak current from the power amplifier and the light source occurs simultaneously, the battery has to deliver a current of several amperes during several milliseconds. This amount of current may cause a drop in the supply voltage due to the internal resistance of the battery, the resistance of the battery contacts and other resistances in the path between the battery and the electronic components in the phone, which could cause a crash of the software running on the mobile telephone.

Accordingly, to operate the light source and the transceiver simultaneously additional measures are required. A possible solution is to include ‘super’ capacitors in the transceiver to provide the amount of current required to operate the flash light and the transceiver simultaneously. However, a disadvantage is that capacitors occupy a large amount of space. Accordingly, the transceiver would be relatively large. Furthermore, in case the transceiver is implemented as an integrated circuit, the capacitors would increase the amount of substrate area required for the circuit. This increases the costs of the circuit significantly, since the substrate area is a significant factor in the costs of an integrated circuit. Also, the ‘super’ capacitors introduce complex mechanical constraints.

SUMMARY OF THE INVENTION

The present invention provides a mobile communications device, a controller, a method for operating a mobile communication device and a kit of parts as described in the accompanying claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1andFIG. 2schematically show block diagrams of examples of a mobile communications device1. The mobile communication device may, as shown inFIG. 1andFIG. 2, include a communication unit2and one or more other components such as a back light source14, and/or a display15, and/or a camera5and/or a light source6. The mobile communication device1may further include one or more controllers, such as for example a camera controller3and/or a light source controller4.

As shown inFIGS. 1 and 2, one or more of the controllers3,4may be connected to the communication unit2and to one or more of the other components. For instance, in the example ofFIG. 2, the light source controller4is connected to the communication unit2and respective light sources6,14. The light source controller4can control the light sources6,14during at least a part of a time the communication unit2is in a communicating mode based on an operation of the communication unit2.

The light source controller4may for instance be connected to a control output20of the communication unit2to determine a state of the communication unit2and be connected to respective control inputs60,140of the one or more other components (e.g. of the light sources6,14) in order to change a state of the component, when the communication unit2enters into a predetermined state during at least a part of the communicating mode, from a first state to a second state at which the component has a lower energy consumption than in the first state. For example, during the communicating mode, the communication unit2may for instance be in a transmitting state in which the communication unit2transmits signals to the other device or in a non-transmitting state (e.g. in a receiving state or in a sleeping state) in which the communication unit2does not transmit signals to the other device. The controller may then control, for example, the other components based on whether the communication unit2is in the transmitting state or a non-transmitting state. For instance, the light source controller4may switch the light sources6,14to a less bright mode.

The mobile communications device1may for example include one or more components from the group consisting of: back light, display, camera, light source, microphone, speaker, voice processor communication processor, base-band processor. The components other than the communication unit2may, for example, be components not required to transmit signals. E.g. such as components providing other functionality than voice communication, such as the light source, the camera, the back light, or the display.

As shown inFIG. 2, the mobile communications device1may for example include a display15at which information can be outputted visually. For example, data, images, video or other visual information may be outputted at the display15by a processor8. The mobile communications device1may include a back light14which projects light onto a back side from the display15, in order to illuminate the side of the display facing a user and thereby enhance the legibility of the display15.

As shown inFIGS. 1 and 2, the mobile communications device1may for example include a camera5which can capture an image of an object (or of a number of objects). A camera controller3may, as shown inFIG. 1, be connected to the camera5. In the example ofFIG. 1, for instance, a camera control output31of the camera controller3is connected to the camera5. The camera controller3may control one or more parameters of the camera5, such as the timing of capturing an image by the camera5, the sensitivity of the camera5to light, the zoom of the camera5, the focal plane of the camera5or other suitable parameters.

In order to enable the camera5to capture an amount of light from an object sufficient to capture the image, the light source6can illuminate the object by projecting light on the object. The light source controller4may be connected to the light source6. As shown inFIG. 1, for instance, the light source controller4may be connected with a control input60of the light source6. The light source controller4can control one or more parameters of the light source6, such as the operating mode of the light source6, the amount of power used by the light source6, the period of time during which light is projected or any other suitable parameter.

The communication unit2may communicate with another device, for example over a wireless connection. The communication unit2may for instance have a communication mode in which the communication unit2communicates with another device and a non-communication mode in which the communication unit2does not communicate.

For example, when switched into the communication mode, the communication unit2may establish a communication channel over a wired or wireless connection, e.g. a radio connection. The communication unit2may for example establish the communication channel according to a communication protocol, such as define by the Global System for Mobile communication (GSM) standard, or a standard in the IEEE 802 series, such as the 802.11 series. When establishing the communication channel, the communication unit2may for instance be configured according to instructions received from another device, such as a base station of a mobile telephone network. When switched into the non-communication mode, the communication unit2may close the communication channel, and for instance be reconfigured. The communication channel may for example be a bi-directional channel via which the communication unit2may transmit and/or receive signals.

The communication unit2may for example be in the communicating mode during a voice call, and be in a non-communicating mode before and after the voice call (when, for instance, the mobile communication device1is not used for communication but for example to run software applications, such as a game application or a calendar application). For example, the communication unit2may alternate in the communicating mode between a transmitting state in which signals are transmitted by the communication unit2and a receiving state in which signals are receiving by the communication unit2. The communication unit2may for example allocated a certain period of time to transmit and a certain period of time to receive signals by a base station or other network controlling device. For example, in a wireless communication networks, such as GSM, a mobile communications device typically is assigned a certain period of time to receive signals and to transmit signals.

In the examples ofFIGS. 1 and 2, for instance, the communication unit2is connected, with a signal output21, to an antenna7and can receive and/or transmit electromagnetic signals, such as radio signals, over a (not shown) wireless connection to another device, such as a base station of a mobile telephone network. The communicating mode of the communication unit2may include a transmitting state in which the communication unit2transmit signals to the other device and a non-transmitting state in which the communication unit2does not transmit signals (but for example receives signals) to the other device. The light source controller4may be arranged to control the light source6to be in a first state when the communication unit2is in the transmitting state, and control the light source6to be in a second state when the communication unit2is in the non-transmitting state, such that in the first state the light source6emits less light than in the second state.

The light source controller4may for example control the light source6and/or the backlight14during at least a part of the communicating mode of the communication unit2based on an operation of the communication unit2and on an operation of the camera5. Thereby, for example, the light source6may be prevented from affecting the communication between the mobile communications device1and another device. Also, for example, the need to provide additional circuitry, such as capacitors, to enable the light source6and/or the backlight14to use the same power source as the communication unit2may be obviated. For instance, as is explained below in more detail with reference toFIG. 3, the light source controller4may control the light source6to emit light depending on the power consumption of the communication unit2when the communication unit2is in the communicating mode. Without whishing to be bound to any theory, it is found that with such a control, an effective illumination of the object may be obtained without adversely affecting the operation of the communication unit2. For instance, an excessive consumption of power from a power source may be prevented by controlling the power consumption of the light source6such that the power consumption of the light source6is reduced when the power consumption of the communication unit2increases during the communication mode or vice versa.

As shown inFIG. 6, the mobile communications device1may include a housing13in which at least a part of the units shown inFIG. 1(or the units shown inFIG. 2) may be provided. In the example ofFIG. 6, the housing13has a passage in which a part of the camera5is placed, more in particular an optical element, such as lens, which can guide light from the object onto light sensitive elements, such as charge coupled devices. The light source6may for example be mounted in the housing13, such that the light generated by the light source6is projected in the viewing direction of the camera5. In the example ofFIG. 6, for instance, the light source6is present in a passage in the housing13and can project at least a part of the light in a focussing direction of the optical element, and hence illuminate objects in the viewing area of the camera5.

The light source controller4may be implemented in any suitable manner. The light source controller4may, for instance, be connected to the camera controller3and the communication unit2. InFIG. 1, for instance, a first controller input40is connected to a control output30of the camera controller3. A second controller input41is connected to a control output20of the communication unit2. Via the controller inputs40,41, the light source controller4may receive signals from the camera controller3and the communication unit2containing information about the operation of the camera5and the communication unit2. The light source controller4may for example control the amount of current used by the light source6based on the received signals or any other parameter of the light source6suitable for the specific implementation.

The light source controller4may, for example, receive information about the mode of the camera5and/or the communication unit3and compare the receive information with one or more control criteria. Based on the comparison, the light source controller4may control the light source6. For example, the light source controller4may control the mode of the light source6. For example, the light source controller4may switch the light source6from a first mode to a second mode based on the comparison. The light source controller4may for example be arranged to switch the light source6from an on-mode to an off-mode, or vice versa, depending on the signals received from the camera controller3. The light source controller4may for example switch the light source6on when the camera5capture an image and switch the light source off when the camera5is not operating.

In the on-mode, the light source6may for example be switched between states in which differing intensities of the light emitted by the light source6depending on the state of the communication unit2. Thereby, excessive power consumption by the mobile communications device1can be prevented effectively, since the communication unit2consumes a significant amount of power during the transmitting state and the power consumption of the light source6corresponds to the brightness of the light source6. The light source controller4may for example switch the light source6from an intense mode to a less intense mode, in which less light is emitted by the light source6but the light source is still emitting light, when the communication unit2switches from the receiving state to the transmitting state (and switch the light source6from the less intense mode to the intense mode when the communication unit2switches from the transmitting state to the receiving state). The light source6may for example be in a flash mode when the communication unit2is in the receiving state and be set in a video mode when the communication unit2is in the transmitting state.

The transmitting state may for example have duration in time which is less than a time required to capture an image with the camera5. For example, the camera5may be able to capture between 10 and 50 images per second (fps), for example 15 of 30 fps. The communication unit2may alternate between the receiving state and the transmitting state with a period of 10 ms or less, such as 4 ms. The communication unit2may for example alternate between the transmitting state and the receiving state, with a duty cycle of 50% or less and/or above 12.5%. The communication unit2may alternate between the receiving state and the transmitting state in cycles of 10 ms or less, such as 4 ms. During a cycle the communication unit2may for example be in the transmitting state for a period in the range from 0.5 milliseconds (ms) to 2 ms and/or be in the receiving state for a period in the range from 2 ms seconds to 3.5 ms.

The light source6may be implemented in any suitable manner. The light source6may, as shown inFIG. 1for example, include a light emitting diode (LED) which is connected with anode contact60to the light source controller4and with a cathode contact61to ground GND. The light source6may for example be operated as a flash light or as a continuous light source. For instance, when the camera5is used to capture a single image, the light source may be operated as a flash light and when the camera5is used to capture a sequence of images, i.e. a video, the light source6may be operated as a continuous light source. For example, the light source6may include a LED which uses a current of about 200 mA when operated as a continuous light source and in the range from 1 A up to and including about 1.5 A when used as a flash light, with a supply voltage in the range of 0.38 V to 4 V.

FIG. 2shows another example of a mobile communication device100. The mobile communication device100may, as shown inFIG. 2, include a power source10connected to the communication unit2and the light source6. The power source10may for example be a voltage source or a current source. The power source10may for instance be a DC power source, such as a battery, a lithium-based chemical battery for example. The communication unit2and the light source6may for instance use the same power source10. The power source10may provide power to the communication unit2and the light source6. In the example ofFIG. 2, the light source6is connected to the power source10via the light source controller4. More in particular, a current input60of the light source6, in this example a light emitting diode, is connected to a power output43of the light source controller4. A current output61of the light source6is connected to ground GND. A current input44of the light source controller4is directly connected to the power source10.

In the example ofFIG. 2, the back light14is also connected to the power source10via the light source controller4. More in particular, a current input140of the back light14, in this example a light emitting diode, is connected to a power output43of the light source controller4. A current output141of the back light14is connected to ground GND.

The light source controller4may be connected to a power input of the communication unit2and may be arranged to control the light source6and/or the backlight14based on a consumption of power from the power source by the communication unit2. In the example ofFIG. 2, for instance, the communication unit2includes a power amplifier24and a modem23. In this respect it should be noted, the term ‘modem’ as used in this application refers to a device which converts a received signal into a form suitable for a communication system. The modem may, for example, convert a received signal into a form suitable to be processed by upper layers of a communication protocol. The modem may, for example, use hardware resources, such as one or more processors and memories to perform demodulation, decoding functions and to process low level protocol layers and may execute software.

The modem23may, for example, receive signals (to be sent to another device) from a base-band unit8connected with a base-band output80to a modem input230. The base-band unit8may for instance present a base-band signal to the modem input230. The modem23may convert the base-band signal into a signal suitable to be transmitted over the connection. The modem23may for example convert the base-band signal into a modulated signal with a carrier frequency different from the frequency of the base-band signal, and present the signal to a signal input240of the power amplifier24, to transmit the signal to another device via the antenna7.

The modem23may further control the power provided to the power amplifier24, and hence the power consumption thereof. The modem23may, as shown inFIG. 2, for example have a power control output234connected to an on/off contact244of the power amplifier24. Via the on/off contact244the power amplifier24can be switched on or off by either providing a high voltage or a low voltage. The modem23can control the voltage of the on/off contact244, and hence switch the power amplifier24on or off. The modem23may for example switch the power amplifier24on, and hence into a transmitting state by setting the voltage to a high voltage and switch the amplifier24off by setting the voltage to a low voltage. In the example ofFIG. 2, the light source controller4is connected with a third controller input42to the on/off contact244. The light source controller4can thus sense the voltage supplied to the on/off contact244and hence control the light source6based on the state of the power amplifier24. The light source controller4may, as shown inFIG. 3for example, include power supply control units45,46which connect the light source6to the power supply10and control the power supply control units45,46based on the voltage supplied to the power amplifier, as is explained below in more detail with reference toFIG. 3.

The power amplifier24may further have one or more (two inFIG. 2) signal inputs240,241. At the signal inputs240,241one or more signals to be amplified may be presented. The power amplifier24is connected with a signal output242to the signal output21, and hence to the antenna. The amplifier24can present an amplifier signal to the antenna7, in order to transmit the signal to another device via a wireless connection. The signal inputs240,241may, as shown inFIG. 2, be connected to signal outputs231,232of the modem23and the modem23may generate and present the signals to be amplified to the signal input(s)240,241.

The power amplifier24may, as shown inFIG. 2, be connected with a power supply contact243to the power supply10. Between the power supply10and the power amplifier24a voltage converter25may be present. In the example ofFIG. 2, for instance, a voltage converter25is connected with a low voltage contact251to the power source10and with a high voltage contact250to the power amplifier24. The voltage converter25can convert the voltage provided by the power source10to a higher voltage, for example from a voltage below 5 V, such as 3.7 V, to a voltage above 10 V, such as 12 V or 15 V. In the example ofFIG. 2, a converter control contact252of the converter25is connected to a converter control output233of the modem. Via the converter control contact252, for example, the voltage conversion ratio may be controlled.

The light source controller4may include a first controller input40connected to the camera controller3. In the example ofFIG. 2, the first controller input and the second controller input41are connected to a processor8. The processor8is connected with a supply85to the power source10. The processor8is connected with an input/output80to the communication unit, to receive or transmit signals from and to the communication unit. The processor8is further connected with a first light source control output81to the first controller input40of the light source controller4. A second light source control output82of the processor8is connected to the second controller input41of the light source controller4. At the first light source control output81, the processor8can output a signal which controls the mode of the light source, e.g. on or off. For example, when the camera5captures an image, the mode may be controlled to be the on-mode whereas the mode may be set to be the off-mode when the camera5does not capture an image. At the second light source control input82, a signal can be presented which controls the state of the light source, e.g. high level of light or low level of light. For example, when the camera is used as a video camera, the level of light may be controlled by the processor8to be low, and in case the camera is used as a photo camera, the level of light may be controlled to be high.

In the example ofFIG. 2, a camera control output83of the processor is connected to the control input30of the camera controller3. The processor8may for example transmit to the camera controller3a start signal in response to which the camera controller3starts generation of an image and/or receive from the camera controller3data representing one or more images and output the images, for example at a (not shown) user interface in a for humans perceptible form. When the start signal is being sent, or slightly prior thereto, the processor8may e.g. set light source6in the on-mode via the first light source control output81.

In the example ofFIG. 2, a communications input/output84of the processor8is connected to an input/output90of a voice communication processor9. The voice communication processor9is connected to a microphone11and to a speaker12, via respective signal inputs/outputs91,92. The voice communication processor9can control the microphone11and the speaker12and process signals received from the microphone or to be outputted at the speaker12.

Referring toFIG. 3, the light source controller4may be connected with the first controller input40to the first light source control output81. Via the first controller input40, the mode of the light source can be controlled, e.g. on or off, as shown in table 1. As shown inFIG. 3, the light source controller may include a comparator unit. The comparator unit may compare the signal at the second controller input and the signal at the third controller input with a light source control criterion, which comparator unit may be further connected to the controller output, for controlling the light source based on a result of the comparison.

In the example ofFIG. 3, for example, the comparator includes a logic exclusive AND (XAND) gate48. The XAND gate48is connected with an input to the second controller input41and with an inverted input to the third controller input42. The XAND gate48is connected with an output to a control input of a switch47. The switch47connects a power supply port44, which can be connected to the power source10, to a selected one of power supply control units45,46. The power supply control units45,46are connected to the power output43. The power supply control units45,46each provide a different amount of power to the power output43, and hence to the light source. The state of the switch47is controlled by the signal presented at the switch control input, and hence by the output of the XAND gate48. Depending on the state of the switch47, the power supply control unit45or the other power supply unit46is connected to the power supply and hence either a first current or a second current is supplied to the light source6. Table 1 is a truth table which lists the state and mode of the light sources6and the state of the backlight14as a function of the signal presented at the inputs40-42.

The controller4may include a comparator49for sensing comparing a parameter forming a measure for an amount of energy available from the power source10with a predetermined control criterion and controlling the state of the component based on the comparison. In the example ofFIG. 3, for instance, the input44forms a sensing contact and is connected to an input of a comparator49. The comparator49can compare the voltage at the input with a threshold voltage TR at reference input. The comparator49may for example output a logical true signal (e.g. a 1) in case the voltage at the input is higher than the threshold voltage and output a logical false signal (e.g. a 0) in case the voltage at the first input is lower than the threshold voltage. As shown inFIG. 3, the comparator49may for example be connected to the input42, and hence control the switch as explained above. Thereby, in case the supply voltage of the power source10, which may for example be a battery, becomes below the threshold voltage, the light source6,14may be switched to a lower consumption mode. Since the supply voltage forms a measure for the energy in a battery, and typically reduces when the battery is almost empty, the lifetime of the power source can be extended.

The camera5may be any suitable type of camera. In the example ofFIG. 1, for instance, the camera is a digital camera. The digital camera may, as shown, include a matrix-like sensor which includes a plurality of a sensor elements51-5iarranged in rows and columns, such as charge coupled device sensors, complementary metal-oxide semiconductor (CMOS) sensors or another suitable type of photo-sensor. As shown inFIG. 1, the camera5may include a lens51or other optical element which projects light onto the matrix of sensor elements51-5i. For illustrative purposes, inFIG. 1a line-shape arrangement of five sensors is shown and inFIG. 2a two-dimensional matrix arrangement of five-by-five sensors is shown. However the matrix arrangement may include any suitable number of n by m sensors, with m equal or different to n. The matrix may for example be an array of more than 500 pixels by more than 400 pixels, 640 by 480 pixels or 2048 by 1536 pixels. The arrangement may for example be rectangular and for example have a length:width ratio of 1.25 or more, such as 1.33 or more, for example 1.77 or more.

The camera controller3may be implemented in any suitable manner. The camera controller3may for example be arranged to send the captured image to another device. In the example ofFIG. 1, for instance, the camera controller3is connected with an image output33to an image input22of the communication unit2. The camera controller3can send data representing the captured image to the communication unit2, via the image output33and the image input22. The communication unit2may subsequently transmit the data to another device, for example via the antenna7and a wireless connection to the other device. However, the image may also be captured for different purposes, and for example be stored in a (not shown) memory in the mobile communications device1or be outputted on a (not shown) display.

The light source controller4may for example control the light source to be in the on-mode during a period of time longer than inverse of the number of images the camera can capture per seconds, for example about two times or more than two times that period. Thereby, the light source is controlled in a manner which may be used to project light on an object of which camera without mechanical shutter, such as a so-called rolling-shutter camera, captures an image. In table 2, examples of values for the duration of the flash light are listed as a function of the number of frames the camera may capture.

TABLE 2Camera speed equal or larger than:Time of flash equal or larger than:(frames per second)(ms)7.527210205151382010525853072

FIG. 4schematically illustrates generation of an image with a rolling-shutter camera. A rolling-shutter camera may include a matrix arrangement of photo-sensitive sensor elements51-5i, as e.g. shown inFIGS. 1 and 2. When capturing an image, a sub-image is captured per line of the matrix and the sub-images are combined thereafter into the complete image. More in particular, a line-shaped subgroup of photo-sensitive cells is activated, the light is projected onto the cells51-5iin the respective line during an exposure period. Following the exposure time, the sensor elements are read out and the sensor elements are reset to provide a defined exposure time. Using a data-processing unit, for example the camera controller3, which has suitable means of processing such as, for instance, means of digitizing, storing, calculation, etc., an image can be produced from the read lines. As is illustrated inFIG. 4, the camera may capture an image Fn which may be part of a sequence of images . . . , Fn−1, Fn, Fn+1, . . . or be a single separate image. As illustrated, when capturing the image Fn, the line of sensor elements denoted511-5i1is first activated, exposed and readout. Thereafter, the process is repeated with a following line512-5i2, etc., until the last line of elements denoted51j-5ijinFIG. 2is activated, exposed and readout. In the example ofFIG. 4, the lines are read after each other in the period of time denoted T2, but the processes for the lines have an overlap in time. The last line is activated a period of time T1after activation of the first line.

FIG. 5schematically illustrates the current Ibat provided by the power source10, the current Ifls used by the light source6and the current Itrx used by the communication unit2in the communicating mode. For illustrative purposes, the graphs have not been drawn to scale to help improve the understanding of the embodiments of the present invention. As shown, the communication unit2may switched in the communicating mode between a transmitting state in which a high amount of current, for example more than 0.5 mA, such as 1.5 mA, or more, is used by the communication unit2and a receiving state in which a low amount of current is used by the communication unit2for example less than 0.4 mA such as 0.3 mA. The switching between the transmitting state and the receiving state may for example have a period which is less than the time required to capture an image, for example less than 5 ms, such as 4.6 ms. The switching may for example which is less than the time required to activate, expose, read and reset a line of a sensor elements51j-5ij. The ratio of the switching period relative to time required to activate, expose, read and reset a line may for example be in the range of 1:20 to 1:5. The light source6is switched to an on-mode when the camera5starts capturing the image Fn, and switched to off-mode when the last line of elements denoted51j-5ijhas been read out. In the on-mode, the light source6is switched between the high state and the low state when the communication unit2is switched between the transmitting state and the receiving state. Accordingly, as shown inFIG. 4, the current provided by the power source10remains relatively low.

The invention may be implemented as a kit. The kit may be provided as a set of separate components which can be connected to each other to assemble a module operating as controller4, or may be provided as an assembled module of components connected to each other in a suitable manner.

The invention may also be implemented in a computer program for running on a computer system, at least including code portions for performing steps of a method according to the invention when run on a programmable apparatus, such as a computer system or enabling a programmable apparatus to perform functions of a device or system according to the invention. Such a computer program may be provided on a data carrier, such as a CD-ROM or diskette, stored with data loadable in a memory of a computer system, the data representing the computer program. The data carrier may further be a data connection, such as a telephone cable or a wireless connection.

In the foregoing specification, the invention has been described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein without departing from the broader spirit and scope of the invention as set forth in the appended claims. For example, other components, such as the speaker12or the voice communication processor9, may be controlled based on the operation of the communication unit2and for example be switched on or off depending on the state of the communication unit2.

For example, it should be understood that all circuitry described herein may be implemented as one or more integrated circuits, for example implemented in silicon or another semiconductor material or alternatively be implemented as a software code representation of one or more integrated circuits or parts thereof.

Also, the invention is not limited to physical devices or units implemented in non-programmable hardware but can also be applied in programmable devices or units able to perform the desired device functions by operating in accordance with suitable program code. Furthermore, the devices may be physically distributed over a number of apparatuses, while functionally operating as a single device. For example, the light source controller10and/or the communication unit2may be implemented as suitably connected discrete semiconductor components.

Also, devices functionally forming separate devices may be integrated in a single physical device. For example, the base-band unit8, the light source controller4, and the voice communication processor9may be integrated into a single processor.

Furthermore, the mobile communications device may, for example, be a mobile telephone, a personal digital assistant, a camera provide with a wireless communication unit to enable transmission of captured images or video to, e.g., a person computer or another type of mobile communication device.