Portable wireless communications unit and lighting control method thereof
First Claim
1. A portable type wireless communications unit comprising:
- a battery for supplying electrical current to said communications unit;
voltage sensing means for detecting a voltage at terminals of said battery;
lighting means to light said communications unit using said electrical current;
a transmission and a reception section for performing a time sharing operation; and
lighting control means for regulating by said time sharing operation a periodic supply of said electrical current to said lighting means and for stopping the supply of electrical current for at least an interval of said transmission,wherein a duration of said interval during which the supply of said electrical current to said lighting means is stopped is controlled according to said voltage detected at said terminals of said battery.
2 Assignments
0 Petitions
Accused Products
Abstract
A backlight for a liquid crystal display in TMDA type portable telephones is driven by PWM. A register for holding the PWM-drive pulse width setting values and a decoder for decoding counted values in a base counter for counting the basic timing of three slots for receive, idle and transmit. A lighting control circuit Scb is provided to cut off the supply of power to the backlight incandescent lamp from the secondary battery during the transmit time slot. The power cutoff period by means of the Scb signal may be extended beyond the transmit time slot depending on the voltage detected at the secondary battery terminal by means of a voltage sensor circuit. Consequently additional voltage drops in a battery can be avoided during transmission in a TMDA type portable telephone by switching off a light such as a backlight for a liquid crystal display.
25 Citations
14 Claims
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1. A portable type wireless communications unit comprising:
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a battery for supplying electrical current to said communications unit; voltage sensing means for detecting a voltage at terminals of said battery; lighting means to light said communications unit using said electrical current; a transmission and a reception section for performing a time sharing operation; and lighting control means for regulating by said time sharing operation a periodic supply of said electrical current to said lighting means and for stopping the supply of electrical current for at least an interval of said transmission, wherein a duration of said interval during which the supply of said electrical current to said lighting means is stopped is controlled according to said voltage detected at said terminals of said battery. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of operating a portable type wireless communications unit, comprising the steps of:
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supplying electrical current to a communications unit from a battery; detecting a voltage at terminals of said battery using voltage sensing means; lighting up a terminal with lighting means; performing a time sharing operation with a transmission and a reception section; and regulating a periodic supply of said electrical current and the time sharing operation of a lighting control means so that the supply of electrical current to said lighting means is stopped for at least an interval of a transmission, wherein a duration of said interval during which the supply of said electrical current to said lighting means is stopped is controlled according to said voltage detected at said terminals of said battery. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification