Electric lamp and discharge devices: systems – Cathode ray tube circuits – Cathode-ray deflections circuits
Reexamination Certificate
2000-08-08
2001-10-02
Wong, Don (Department: 2821)
Electric lamp and discharge devices: systems
Cathode ray tube circuits
Cathode-ray deflections circuits
C315S411000, C361S018000, C363S021030
Reexamination Certificate
active
06297601
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to an electric power supply apparatus for a display system and, more particularly, to an apparatus and a method for saving electric power in a display system in which, when the display system is turned to an off mode, total electric power consumption is reduced to a range wherein the display system can be operated through a reduction of an on-duty time period of a pulse width modulation (PWM) pulse by using a charging/discharging device of large capacitance.
2. Related Art
Most display systems appearing on the market recently are equipped with an electric power-saving mode. The power-saving mode proceeds sequentially through a normal mode, a suspend mode, a standby mode, and an off mode, depending on whether or not horizontal and vertical synchronization signals from a video card built into the main body of a computer are inputted.
The off mode is applied when neither the horizontal nor vertical synchronization signals are inputted from the video card in the main body of the computer.
Specifically, the off mode is used to minimize electric power consumption in a display system by cutting off electric power supplied to all parts of the computer when a user does not use the display system, that is, when it is determined, as a result of a detection process, that neither horizontal nor vertical synchronization signals are inputted.
In the off mode, a microcomputer is still supplied with sufficient electric power to enable the display system to be turned to the normal mode when horizontal and vertical synchronization signals are inputted from the video card in the main body of the computer.
In such a system as generally described above, the power savings achieved are limited, even when the system is placed in the off mode. This is due to the fact that, even when in the off mode, the system must provide power to the microcomputer so that it can continue to monitor the status of a signal input from the computer main body in order to determine whether horizontal and vertical synchronization signals are being inputted from a video cord in the computer main body. Since, in such a system as described above, power must be provided to the microcomputer at all times, satisfactory power savings cannot be achieved.
SUMMARY OF THE INVENTION
In order to solve the above problem, it is an object of the present invention to provide an apparatus and a method for saving electric power in a display system in which, when the display system is turned to an off mode, total electric power consumption is reduced to a range wherein the display system can be operated through a reduction of an on-duty time period of a PWM pulse by using a charging/discharging device of a large capacitance.
In order to achieve the above object, according to the present invention, an electric power-saving apparatus for a display system provides an electric power-saving mode as an off mode through a reduction of electric power consumed in an entire system when horizontal and vertical synchronization signals are not inputted from a computer main body during a predetermined time period. The apparatus comprises: an electric power supply control part for selectively generating a PWM pulse of a PWM circuit section in response to an electric power supply control signal inputted from an external source; an operational voltage supply part for generating an operational voltage, wherein the operational voltage supply part is charged with energy induced in a secondary winding of a switching transformer when the PWM pulse is generated by the PWM circuit section under the control of the electric power supply control part, and commercial electric power is supplied to a primary winding of the switching transformer and the operational voltage supply part is discharged when the PWM pulse is not generated under the control of the electric power supply control part; and a microcomputer which is driven based on the operational voltage inputted from the operational voltage supply part for switching the entire system into the off mode when the horizontal and vertical synchronization signals are not inputted from the computer main body,and for outputting the electric supply control signal in order for the PWM pulse to be generated as soon as a remaining voltage becomes lower than a minimum value of an input compensation voltage of the operational voltage supply part when the operational voltage supply part is discharged.
Further, in order to achieve the above object, according to the present invention, an electric power-saving apparatus for a display system provides an electric power-saving mode as an off mode through a reduction of electric power consumed in an entire system when horizontal and vertical synchronization signals are not inputted from a computer main body during a predetermined time period. The apparatus comprises: an electric power supply control part for selectively supplying commercial electric power provided to a primary winding of a switching transformer in response to an electric power supply control signal inputted from an external source; an operational voltage supply part which is charged with energy induced in a secondary winding of the switching transformer in response to a PWM pulse when the commercial electric power is supplied to the primary winding of the switching transformer under control of the electric power supply control part, and which is discharged when the commercial electric power is not supplied to the primary winding of the switching transformer under control of the electric power supply control part; and a microcomputer which is driven based on the operational voltage inputted from the operational voltage supply part for switching the entire system into the off mode when the horizontal and vertical synchronization signals are not inputted from the computer main body, and for outputting the electric supply control signal in order for the commercial electric power to be supplied to the primary winding of the switching transformer as soon as a remaining voltage becomes lower than a minimum value of an input compensation voltage of the operational voltage supply part when the operational voltage supply part is discharged.
Furthermore, in order to achieve the above object, according to the present invention, an electric power-saving method for a display system comprises the steps of: (1) determining whether horizontal and vertical synchronization signals are inputted from a computer main body; (2) performing a normal mode of operation when the horizontal and vertical synchronization signals are inputted from the computer main body, switching the entire system into an off mode when the horizontal and vertical synchronization signals are not inputted by outputting a turn-off signal to cut off a voltage supplied to each load, and outputting an electric power supply control signal to selectively control an induction of energy in a secondary winding of the switching transformer; (3) outputting the electric power supply control signal and then counting a time period; (4) determining if the counted time period is the same as a predetermined time period; (5) determining whether the horizontal and vertical synchronization signals are inputted from the computer main body when the counted time period is the same as the predetermined time period; (6) setting the electric power supply control signal to a turn-off state before switching the entire system from the off mode to a normal mode when the horizontal and vertical synchronization signals are inputted from the computer main body, and outputting a turn-on signal for supplying the voltage to each load; and (7) outputting the electric power supply control signal for energy not to be induced in the secondary winding of the switching transformer when the horizontal and vertical synchronization signals are not inputted from the computer main body.
REFERENCES:
patent: 5751925 (1998-05-01), Kataoka et al.
patent: 5917716 (1999-06-01), Cho
patent: 5961647 (1999-10-01), Kim et al.
patent: 5994852 (1999
Bushnell , Esq. Robert E.
Samsung Electronics Co,. Ltd.
Tran Thuy Vinh
Wong Don
LandOfFree
Apparatus and method for saving electric power in a display... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for saving electric power in a display..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for saving electric power in a display... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2571429