JP2004519936A - System and method for backlight control in a wireless communication device - Google Patents

Abstract

A wireless communication device (100) includes a display (120) having a backlight (124). The backlight controller (126) selectively enables the backlight (124) to minimize power consumption and save energy in the battery (132). In one embodiment, the receiver (110) receives a time of day message from a remote location and sets a timer (122) with the current time of day. The current time of the day is compared to a predetermined time of the day, and the backlight controller (126) enables and disables the backlight (124) at the predetermined time of the day.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is generally directed to wireless communication devices, and more particularly, to systems and methods for controlling a backlight in a wireless communication device.
[0002]
[Prior art]
Wireless communication devices, such as cellular telephones, typically include a keypad and a display. The display contains a number of lines of alphanumeric characters that provide instructions to the user to operate the device, provide feedback in response to user activation of a selected button on the keypad, and provide incoming calls. Provide other data representations, such as data related to.
[0003]
A common display type uses a liquid crystal display (LCD). The reason is low cost, legibility and low power consumption. The disadvantage of LCDs is that they are poorly legible at low ambient light levels. A typical LCD includes a backlight for lighting the display, thereby improving readability. The backlight is typically an incandescent light and consumes significantly more power than the LDC itself.
[0004]
Typical wireless communication devices are battery powered. Saving battery power is important in increasing the operating life of the device. Activating a backlight for an LCD display consumes a large amount of battery power, thus reducing the operating time of the device.
[0005]
[Problems to be solved by the invention]
Thus, it can be seen that there is a great need for a wireless communication device that provides a backlight that improves readability and conserves battery power. The present invention provides this and other advantages which will become apparent from the following detailed description and drawings.
[0006]
[Means for Solving the Problems]
The present invention is implemented in a system and method for controlling a display light in a wireless communication device. In one embodiment, the system includes a receiver that receives a communication signal from a location remote from the receiver. The system also includes a display and a display light, the display light being selectively enabled by the enable signal. The light controller generates an enable signal based at least in part on the signal received by the receiver.
[0007]
In one embodiment, the receiver receives a time of day signal from a remote location, and the light controller generates an enable signal based on the time of day. The system further includes a photosensor element for detecting ambient light and generating a signal related to the level of ambient light. In this embodiment, the light controller generates an enable signal based on the time of day and the level of ambient light. The light controller may generate an enable signal based on the time of the day for a first predetermined portion of the day and based on the level of ambient light for the remainder of the day. .
[0008]
In another embodiment, the receiver receives a positioning signal from a remote location, and the light controller generates an enable signal based on the location of the receiver. This embodiment includes a photosensor element such that the light control generates an enable signal based on the position of the receiver and based on ambient light.
[0009]
In yet another alternative embodiment, the light controller may generate the enable signal based solely on the level of the ambient light and the signal generated by the photosensor element. If the level of the ambient light drops below a predetermined threshold, the light controller generates an enable signal, and if the ambient light level is above a second predetermined threshold. , The generation of the enable signal may be stopped.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention provides intelligent control of the backlight and consequently reduces battery drain. The present invention can be easily realized in any wireless communication device. Although the examples presented herein refer to cellular telephones, the principles of the present invention are applicable to any wireless communication device, including but not limited to analog and wireless devices. Includes digital cellular telephones, personal communication system (PCS) devices, and the like. The present invention is embodied in the system 100 shown in the functional block diagram of FIG. The system 100 includes a central processing unit (CPU) 102, which controls the operation of the system. The memory 104 may include a read only memory (ROM) and a random access memory (RAM), and the RAM 104 provides instructions and data to the CPU 102. A part of the memory 104 may include a nonvolatile random access memory.
[0011]
System 100 is generally embodied in a wireless communication device such as a cellular telephone. System 100 includes a housing 106, which includes a transmitter 108 and a receiver 110, such as transmitter 100 and receiver 110, such as system 100 and a cell site controller (not shown). Enables transmission and reception of data, such as audio communications, to and from a remote location. Receiver 110 and transmitter 108 may be combined with transceiver 112. Antenna 114 is mounted on housing 106 and is electrically coupled to transceiver 112. The operation of transmitter 108, receiver 110 and antenna 114 is well known in the art and need not be described here. Although FIG. 1 illustrates the antenna 114 extending from the housing 106, some designs may include an internal antenna completely contained within the housing. However, transmitter 108, receiver 110, and antenna 114 operate in a conventional manner regardless of the location of the antenna.
[0012]
A keypad 118 that is operated by a user in a conventional manner is mounted on the housing 106. Keypad 118 provides a convenient input device by which a user can enter a destination telephone number and commands.
[0013]
The system 100 also includes a display 120. Display 120 displays instructions to the user and can be conveniently used to display user input data, such as destination telephone numbers and alphanumeric text, to the user. In an exemplary embodiment of system 100, display 120 displays the time, date, and calling party telephone number of the incoming call received by receiver 112. This information provides the user with a visual cue, thereby assisting the user in operating system 100.
[0014]
The system 100 also includes a timer 122. Timer 122 is typically included in CPU 102. As described in further detail below, system 100 may use timer 122 to determine the time and date. Further, timer 122 may be used to light backlight 124 for a predetermined period of time. The system 100 includes a backlight controller 126 for controlling the backlight 124 for the display 120. As described in further detail below, various alternative embodiments of the backlight controller 126 may be used to control the backlight 124, thereby reducing power consumption in the system 100. Further, different display types may use different forms of lighting, such as liquid crystal display (LCD) or light emitting diode (LED) display side lighting. The term "backlight" is intended to include any form of display illumination, whether it is the display itself or an external illumination source.
[0015]
In one embodiment, system 100 includes a global positioning system (GPS) receiver 128. As is known in the art, GPS includes multiple satellites orbiting the earth. A GPS receiver, such as GPS receiver 128, receives signals from some of the multiple orbiting satellites. Based on the received signal, the precise position of the GPS receiver 128 can be determined with high accuracy. Portable GPS receivers are known in the art and need not be described in further detail here. If the system 100 includes a GPS receiver 128, the position of the system may be used by the backlight controller 126 to enable the backlight 124. The use of the GPS receiver 128 in the backlight controller 126 is described in further detail below.
[0016]
In one embodiment, system 100 includes a photo sensor 130. The photo sensor 130 detects an ambient light level and generates an electric signal related thereto. As described in further detail below, the backlight controller 126 receives an electrical signal from the photosensor 130 and selectively activates the backlight 124 when ambient light falls below a predetermined level. You may let it.
[0017]
The electrical components of system 100 receive power from battery 132, which is attached to and supported by housing 106. In the exemplary embodiment, battery 132 is a rechargeable battery. In other embodiments, system 100 may include a connector (not shown) for connection of an external power source, such as a vehicle power adapter, an AC power adapter, or the like.
[0018]
The various components of system 100 are interconnected by bus system 134. The bus system 134 may include a power bus, a control bus, and a status signal bus in addition to the data bus. However, for clarity, various buses are shown in FIG.
[0019]
The backlight control device 126 may be implemented in various ways. In one embodiment illustrated in FIG. 2, timer 122 receives a time-of-day message from base transceiver station (BTS) 150 through a cell site controller (not shown). The time of day message is used to set timer 122 or the clock at which time is displayed on display 120. The techniques used to send the time of day message to the system 100 are well known in the art and need not be described in further detail here.
[0020]
The backlight controller 126 uses the time of the day to selectively enable or disable the backlight 124 during a predetermined time of day. For example, the backlight controller 126 may be programmed to enable the backlight 124 between 7:00 pm and 7:00 am During this predetermined time period, the backlight controller 126 selectively enables the backlight 124 whenever a button on the keypad 118 is actuated by a user. Further, system 100 may enable backlight 124 when receiving an incoming telephone call. Outside a predetermined time period (eg, between 7:00 and 7 pm), whether a button on keypad 118 is actuated by the user or an incoming message is received by system 100, The backlight controller 126 does not enable the backlight 124. Those skilled in the art will appreciate that the operating times used above are exemplary only and that the present invention is not limited by the specific operating times of the backlight 124. The user can program the activation time using keypad 118 and display 120 in the same manner as used to select other operating parameters of a typical cellular telephone.
[0021]
One advantage of implementing system 100 with time of day messages is that most wireless communication devices (eg, cellular and PCS devices) are already configured to receive time of day messages. The backlight controller 126 is located in the memory 104 and can be easily implemented as a series of software instructions executed by the CPU 102. Thus, minor software modifications to existing hardware allow the system 100 to be implemented using the time of day message.
[0022]
The backlight controller 126 may also enable the backlight 124 using the position information. As described above, system 100 may include a GPS receiver 128. The GPS receiver 128 operates in a known manner to receive signals from a plurality of GPS satellites, one of which is shown as GPS satellite 152 in FIG. Other GPS satellites are not shown in FIG. 2 for clarity. Given the exact location of system 100, backlight controller 126 can determine the exact time of sunset at that location. The backlight controller 126 selectively enables the backlight 124 at sunset relative to the location of the system 100 and selectively disables the backlight 124 at sunrise relative to the location of the system.
[0023]
Those skilled in the art will appreciate that ambient light levels are insufficient for satisfactory operation of the system 100 before sunset or after sunrise. Accordingly, the backlight control device 126 selectively enables the backlight 124 during a predetermined time period before sunset, and selectively disables the backlight 124 during a predetermined time period after sunrise. Thus, satisfactory operation in low ambient light can be enabled. The present invention is not limited by the time of the day during which the backlight 124 is selectively enabled or disabled.
[0024]
The GPS receiver 128 may be used in combination with a time of day message transmitted by the BTS 150. In this embodiment, the backlight controller 126 determines the local time using the time-of-day message and uses the position data from the GPS receiver 128 to determine the exact position of the system 100, Determine the time of sunrise and sunset at that exact location. If the wireless communication device already includes a GPS receiver 128, the backlight controller 126 uses only its position data generated by the GPS receiver or in combination with a time of day message. Thus, it can be easily realized as a series of software instructions.
[0025]
One disadvantage of these embodiments is that they assume that ambient light is always available during daytime hours and never available during nighttime hours. However, the user may enter a darkened room during daytime hours. In this environment, the backlight controller 126 does not operate satisfactorily because the backlight 124 is selectively disabled during daylight hours. Similarly, the backlight controller 126 selectively enables the backlight 124 at night time, even when the user is in a lit room. This latter example does not affect the user's ability to operate the system 100, but does not provide the desired reduction in power consumption and reduces the life of the battery 132 (see FIG. 1) between charge cycles. The system 100 may provide a disable command to allow the user to manually enable or disable the backlight 124. The use of keypad 118 to set optional parameters of system 100 is well known in the art and need not be described here.
[0026]
The system 100 may use only the photosensors 130 or in combination with a time of day message from the BTS 150 and / or location data from the GSP receiver 128. When using only the photosensor 130, the backlight controller 126 receives an electrical signal generated by the photosensor, which indicates the ambient light level. When the ambient light level drops below a predetermined threshold, the backlight controller 126 selectively enables the backlight 124. Those skilled in the art will appreciate that the actual actuation of the backlight 124 occurs when the keypad 118 is actuated by a user or when an incoming message is received. If the ambient light level is above a predetermined threshold, the backlight controller 126 selectively disables the backlight 124.
[0027]
When used in combination with the time of day message, the electrical signal generated by the photosensor 130 is used to effectively override the normal settings provided by the time of day message. For example, the backlight controller 126 may selectively disable the backlight 124 based on a time of day message (eg, daytime). However, if the user enters a darkened room or is in some other low ambient light setting, the electrical signal generated by the photosensor 130 will cause the ambient light level to fall below a predetermined threshold. It is shown that. In this event, the backlight controller 126 overrides the settings based on the time of day message and selectively enables the backlight 124 to automatically provide the backlight when needed.
[0028]
Similarly, the backlight controller may selectively enable backlight 124 based on a time of day message (eg, night time). However, if the user enters a lighted room, or is in a high ambient light setting from anything else, the electrical signal generated by the photosensor 130 will cause the ambient light level to exceed a predetermined threshold. Indicates that it is above. In this event, the backlight controller 126 overrides the settings based on the time-of-day message and selectively disables the backlight 124 to save power and extend the life of the battery 132 between charging cycles. Let it.
[0029]
Photosensor 130 may operate with GPS receiver 128 in a manner similar to overriding normal settings based on position data generated by the GPS receiver. That is, regardless of the settings based on the position data generated by the GPS receiver 128, the backlight controller 126 uses the electrical signal generated by the photosensor 130 to selectively enable or disable the backlight 124. You may let it.
[0030]
The operation of the system 100 with the time of day message is illustrated in the flowchart of FIG. At start 160, the wireless communication device is low on power. In step 162, the system 100 receives a time of day message from the BTS 150 (see FIG. 2). In step 164, the system 100 sets its internal clock. It should be noted that the timer 122 (see FIG. 1) also functions as an internal clock. Those skilled in the art will appreciate that timer 122 may be included within CPU 102. The present invention is not limited by the particular form of timer 122.
[0031]
At decision 166, the system 100 determines whether it is night time. The particular time at which the backlight 124 is selectively enabled or disabled can be pre-programmed into the system 100 or can be selected by the user. For example, system 100 can have a default time, such as 7:00 pm and 7:00 am, to selectively enable or disable backlight 124. Alternatively, the user may change the default time by selecting the appropriate menu on display 120 with keypad 118 using conventional techniques. For example, if the user lives in a high latitude where daylight saving time is long and winter time is short, the user can manually adjust the default time to compensate for seasonal variations in day length.
[0032]
The actual time of day is compared to a predetermined time of backlight operation (ie, a default time or a user programmed time). Decision 166 compares the current time with a predetermined time to determine whether to enable backlight 124. For night time (eg, between 7:00 pm and 7:00 am), the result of decision 166 is yes. In this event, the backlight controller 126 selectively enables the backlight 124 at step 168. Otherwise, the result of decision 166 is NO. In this event, the backlight controller 126 selectively disables the backlight 124 at step 170.
[0033]
As described above, the settings can be overridden based on the time of day using the photo sensor 130 (see FIG. 1). Decisions 174 and 176 are optional steps that can be incorporated into system 100 if photosensor 130 is included. In FIG. 3, the ambient light level is compared to the threshold in decision 174. If the ambient light level is below the threshold, the result of decision 174 is yes, and the system 100 moves to step 168 where the fact that it is not nighttime yet (ie the result of decision 166 was no) Nevertheless, the backlight 124 is enabled.
[0034]
Similarly, at decision 176, system 100 determines whether the ambient light level is above a predetermined threshold. For convenience, the ambient light level threshold used in decisions 174 and 176 may be the same light threshold. However, this is not required for satisfactory operation of the system 100. That is, system 100 may use a first threshold in decision 174 and use a second threshold in decision 176 that is different from the first threshold. If the ambient light level is above a predetermined threshold, the result of decision 176 is YES. In this event, the system 100 moves to step 170 and disables the backlight 124 despite the fact that it is night time (ie, the result of the decision 166 was yes).
[0035]
At decision 180, the system 100 determines whether the user has activated the keypad 118 (see FIG. 1). If the user has activated keypad 118, the result of decision 180 is yes. In this event, at step 184, the backlight controller 126 activates the backlight 124 if the backlight is enabled and does nothing if the backlight is disabled. The system ends operation at step 188. If no keypad activation occurs, the result of decision 180 is no. In this event, system 100 returns to decision 180 and waits for subsequent actuation of keypad 118. To understand the present invention, system 100 is illustrated in the flowchart of FIG. 3 to enter a loop at decision 180 awaiting actuation of keypad 118. However, those skilled in the art will recognize that keypad activation may cause an interrupt to be processed by CPU 102. Thus, in a typical configuration, the system 100 does not enter an endless loop waiting for actuation of the keypad 118. Further, the backlight 124 may be activated in step 184 when the receiver 110 (see FIG. 1) receives an incoming call. Other events, such as voicemail notifications and the like, can also trigger the operation of the backlight 124 if the backlight 124 is selectively enabled. Thus, keypad activation is not the only event that can trigger activation of the backlight 124.
[0036]
The operation of the system 100 with the GPS receiver 128 (see FIG. 1) is shown in FIG. At start 200, system 100 is out of power. At step 202, the GPS receiver 128 receives GPS data from a plurality of GPS satellites 152 (see FIG. 2) and determines the position of the system 100 at step 204. In step 206, the system 100 determines the sunrise and sunset times for the location determined in step 204. System 100 then moves to decision 166 shown in FIG. 3 to determine whether the current time of day corresponds to the sunrise and / or sunset times calculated in step 206. The remaining operations, including disabling the operation of step 168 and enabling the backlight 124 using the ambient light level and disabling the operation of step 170 and disabling the backlight, have already been performed previously. Has been described and need not be described again at this point.
[0037]
Thus, the system 100 effectively provides intelligent control of the backlight 124, thereby saving power. In some embodiments, the present invention can be easily implemented by adding only software instructions and without requiring hardware modifications. For wireless communication devices that include GPS capabilities, the present invention may be implemented with additional software instructions. It should be noted that other forms of positioning, such as triangulation, timing signals from multiple base station transceiver systems 150 (see FIG. 2), or other conventional positioning techniques can be used satisfactorily with system 100. One advantage of positioning data is that lighting can be adjusted to compensate for variations in the length of the day based on the location of the wireless communication device.
[0038]
While various embodiments utilizing the present invention have been described above, the foregoing disclosure is exemplary only, and changes may be made in detail and remain within the broad principles of the invention. For example, system 100 may be implemented using only time of day messages, location data from GPS receiver 128, or electrical signals generated by photosensors 130. However, these various techniques may be combined in various ways to meet different design criteria. Therefore, the present invention should be limited only by the appended claims.
[Brief description of the drawings]
FIG.
FIG. 1 is a functional block diagram of a wireless communication device that realizes the present invention.
FIG. 2
FIG. 2 illustrates the operation of the system of FIG. 1 using data received from an external source.
FIG. 3
FIG. 3 is a flowchart illustrating the operation of the system of FIG. 1 for selectively enabling the backlight based on the time of day.
FIG. 4
FIG. 4 is a flowchart illustrating the operation of the system of FIG. 1 to selectively enable the backlight based on the geographic location of the system.

Claims (36)

In a system for controlling a backlight in a wireless communication device,
A housing,
A receiver for receiving a communication signal from a position distant from the receiver;
A display supported by the housing,
A display light, selectively enabled by the enable signal, for lighting the display;
A light controller for generating an enable signal based at least in part on a signal received by the receiver. The system of claim 1, further comprising a timer that tracks time of day, wherein the light controller generates an enable signal based on time of day. The system of claim 2, wherein the receiver receives a time of day signal from the remote location, and the timer tracks the time of the day using the time of day signal. The system further comprises a photosensor element supported by the housing to detect ambient light and generate a signal related to the level of the ambient light, wherein the light control device generates an enable signal based on the time of day and the level of the ambient light. 3. The system of claim 2, wherein said system generates. The light control device further comprises a photosensor element supported by the housing to detect ambient light and generate a signal related to the level of ambient light, the light control device comprising: 3. The system of claim 2, wherein the enabling signal is generated based on ambient light levels for the rest of the day based on the time of the day. The system of claim 1, wherein the light controller activates a display light when the receiver receives an incoming message when an enable signal is being generated. The system of claim 6, further comprising a keyboard operable by a user, wherein the light control device activates the display lights when the keyboard is operated by the user when the enable signal is generated. The system further includes a timer that measures a predetermined time period when the keyboard is operated by the user, wherein the light control device deactivates the display light when the keyboard is not operated by the user for the predetermined time period. The system of claim 7, wherein 9. The system of claim 8, wherein the predetermined time period measured by the timer is selectable by a user. The system of claim 1, wherein the receiver receives a position signal from a remote location, thereby determining the position of the receiver, and wherein the light controller generates an enable signal based on the position of the receiver. The system of claim 10, wherein the remote location is at least a first satellite, and the location signal from the remote location comprises a global positioning satellite signal. The system of claim 10, further comprising a timer that tracks time of day, wherein the light controller generates an enable signal based on time of day and location of the receiver. 13. The system of claim 12, wherein the receiver receives the day time message from the remote location, and the timer receives the day time message and utilizes it to track the time of the day. The system of claim 10, further comprising a photosensor element for detecting ambient light and generating a signal associated therewith, wherein the light controller generates an enable signal based on a location of the receiver and a level of the ambient light. 15. The system of claim 14, further comprising a timer that tracks a time of day, wherein the light controller generates an enable signal based on a time of day, a location of the receiver, and a level of ambient light. In a system for controlling a backlight in a wireless communication device,
A housing,
A transceiver that transmits a communication signal to a location remote from the transceiver and receives a communication signal from a location away from the transceiver;
A photo sensor element for detecting an ambient light level and generating a signal related thereto;
A display supported by the housing,
A display light selectively enabled on the enable signal and lighting the display;
A light controller that receives the signal generated by the photosensor element and generates an enable signal based on the ambient light level. 17. The system of claim 16, wherein the light controller generates an enable signal when a signal from the photosensor indicates that the level of ambient light is below a predetermined threshold. 17. The system of claim 16, wherein the light controller activates a display light when the transceiver receives an incoming message when an enable signal has been generated. 17. The system of claim 16, further comprising a keyboard operable by a user, wherein the light control device activates the display lights when the keyboard is operated by the user when the enable signal is generated. A timer that measures a predetermined time period when the keyboard is operated by the user, wherein the light control device deactivates the display light when the keyboard is not operated by the user for the predetermined time period. 20. The system according to claim 19, wherein: 21. The system of claim 20, wherein the predetermined time period measured by a timer is selectable by a user. 17. The system of claim 16, further comprising a timer that tracks a time of day, wherein the light controller generates the enable signal based on the time of day and the ambient light level. 23. The system of claim 22, wherein the transceiver receives a time of day signal from the remote location, and the timer tracks the time of the day using the time of day signal. The light control device generates an enable signal based on the ambient light level when a signal from the photosensor indicates that the level of the ambient light is below a predetermined threshold regardless of the time of day. 23. The system of claim 22. 17. The system of claim 16, wherein the transceiver receives a position signal from a remote location, thereby determining a position of the receiver, and wherein the light controller generates an enable signal based on the position of the receiver and the ambient light level. In a method of controlling a backlight in a wireless communication device,
Receives the signal used to control the display light,
Display the data on the display,
A method comprising selectively enabling a display light based on a received signal to light the display. Detecting the ambient light level and generating a signal related thereto, wherein the received signal controlling the display light is a generated signal related to the ambient light level, and the display light has a predetermined ambient light level. 27. The method of claim 26, wherein the method is selectively enabled when a generated signal related to an ambient light level indicates that it is below a threshold. 28. The method of claim 27, further comprising measuring a time of day and selectively enabling display lights based on time of day and ambient light levels. The display light will enable the enable signal based on the ambient light level if the generated signal related to the ambient light level indicates that the level of the ambient light is below a predetermined threshold regardless of the time of day. 29. The method of claim 28, wherein: 27. The method of claim 26, further comprising receiving an incoming message from a remote location, and activating the display light upon receipt of the incoming message when the display light is selectively enabled. 27. The method of claim 26, wherein detecting a user action of the keyboard and activating the display light when the keyboard is operated by a user when the display light is selectively enabled. 32. The method of claim 31, wherein a predetermined time period is measured when the keyboard is operated by the user, and the display light is deactivated if the keyboard is not operated by the user for the predetermined time period. Measuring the time of day and generating a signal related thereto, wherein the received signal controlling the display light is a generated signal related to time of day and the display light is based on the time of day. 27. The method of claim 26, wherein said method is selectively enabled. Receiving a day time message arriving from a remote location and generating a signal associated therewith, wherein the received signal controlling the display light is a generated signal related to the received day time message; 27. The method of claim 26, wherein the lights are selectively enabled based on time of day. The method further includes receiving a position signal from a remote location and determining a position associated therewith, wherein the received signal controlling the display light is a generated signal related to the position, and the display light is selectively enabled based on the position. 27. The method of claim 26. The method of claim 35, wherein the remote location is at least a first satellite, and receiving a position signal from the remote location includes receiving a satellite signal.

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