Flashlight Power Control in Wireless Terminals

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Solution Overview

Problem

Wireless communication terminals face battery power consumption issues due to high power requirements of flashlights, particularly when using white LEDs, which can cause voltage drops and reduce battery performance and increase costs.

Innovation Solution

Implementing an inverted duty cycle for the flashlight power supply relative to the transmitter, ensuring the flashlight is only active during transmitter off periods, thereby avoiding simultaneous high power consumption with the transmitter and reducing voltage drops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a flashlight unit (white LED) is used to illuminate the subject in low light conditions, then camera performance is improved, but battery power consumption increases and voltage drops occur

Engineering Contradiction:
Improveflashlight illuminationVSAvoidbattery power consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The flashlight unit is activated in periodic intervals synchronized with the transmitter's off periods. The control mechanism enables the flashlight only during time slots when the transmitter is not transmitting, creating a periodic on/off pattern that matches the TDMA or CDMA transmission cycle. This periodic action allows the flashlight to provide necessary illumination while the system periodically returns to a low-power state where the transmitter can operate.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts the operation state of the flashlight unit based on the real-time transmission status. The control mechanism monitors whether the transmitter is in transmission mode or idle mode, and accordingly enables or disables the flashlight unit. This dynamic control allows the system to adapt its power consumption profile to match current operational requirements, ensuring illumination is provided only when transmission is not occurring.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the flashlight and transmitter operate simultaneously, then both functions are available, but voltage drops cause the terminal to become inoperative

Engineering Contradiction:
Improvesimultaneous function availabilityVSAvoidterminal operativity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system employs periodic time-division operation where the flashlight and transmitter take turns operating in alternating time slots. During transmission periods, the transmitter is active and the flashlight is disabled. During idle periods, the transmitter is disabled and the flashlight can be activated for illumination. This periodic alternation ensures that high current demands never occur simultaneously, preventing voltage drops that would render the terminal inoperative.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

Instead of allowing both functions to operate simultaneously and managing power distribution, the system inverts the approach by making the functions mutually exclusive in time. The control mechanism is designed to enable the flashlight only when the transmitter is off, and vice versa. This inverted logic of mutual exclusion in time domain solves the voltage drop problem by ensuring that the high power consumption of both devices never coincides.

Inventive Principle:
Principle #13The other way round (Inversion)

3Power

If high power is drawn during transmission periods, then transmission quality is maintained, but battery discharge rate increases

Engineering Contradiction:
Improvetransmission powerVSAvoidbattery discharge rate
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The system utilizes periodic transmission intervals characteristic of TDMA or CDMA protocols, where transmission occurs only in designated time slots rather than continuously. The flashlight is synchronized to operate during the idle periods between transmission slots. This periodic operation pattern allows the transmitter to maintain high power during its active slots for quality transmission, while the overall average power consumption is reduced because both transmitter and flashlight are off during their respective inactive periods.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system maintains continuous useful action by ensuring that while the transmitter is active for communication, the flashlight is ready to activate immediately when transmission ceases. The control mechanism maintains readiness states for both devices, allowing seamless transition between transmission and illumination modes without interruption of overall system functionality. This continuity ensures that communication and illumination needs are both met over time, even if not simultaneously.

Inventive Principle:
Principle #20Continuity of useful action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces battery power consumption, maintains reasonable voltage levels, and decreases the size and cost of battery components by avoiding the need for low ESR batteries and improved battery performance.

Implementation Method 1

One approach to reduce the size and power consumption is to use a light emitting diode (LED) device which may be illuminated when an image is captured by a digital camera built into the wireless terminal

Methodology Applied
Scientific EffectLight emitting diode: Light Emitting Diode

Data Source

PatentEP1961197B1Improvements in a wireless terminal having a flashlight
Publication Date: 2012.07.25 NOKIA CORP
  • EP1961197B1 patent drawingFigure 1~2

AI summary

In a wireless communication terminal having a flashlight, the power consumption is decreased by means of enabling a transmitter to transmit during transmission periods, and disabling the transmitter outside the transmission periods. Moreover, a supply of voltage from a common power supply to a flashlight unit is disabled during the transmitting periods of the transmitter.