Power supply of display apparatus with universal serial bus device

Claim 2

A power supply of display apparatus having universal serial bus (USB) hub, the power supply comprising: a rectifier converting an AC input voltage into a DC output voltage; a first power supply circuitry for generating regulated output voltage required to energize a display when it receives the rectifier output voltage; a second power supply circuitry for supplying power to the USB hub, in which the second power supply circuitry receives said DC output voltage from said rectifier as input to said second power supply circuitry; a power switch disposed between the output of the rectifier and an input of the first power supply circuitry; and a controller outputting a control signal that switches said power switch so that no power is supplied to said first power supply circuitry in response to display power management signals input to said controller, said display power management signals corresponding to a power-off mode.

Claim 3

The power supply of claim 1 , wherein the second power supply circuitry comprises a DC/DC converter for outputting desired voltage to the USB hub.

Claim 4

The power supply of claim 2 , said second power supply circuitry further comprising an auxiliary power supply converting said DC output voltage from said rectifier to a desired DC voltage for input to said DC/DC converter.

Claim 5

The power supply of claim 1 , wherein the first power supply circuitry comprises a switching mode power supply (SMPS) circuitry.

Claim 6

The power supply of claim 1 , wherein the display power management signals comprise a horizontal and a vertical synchronization signal (Hsync, Vsync) provided by a system host.

Claim 7

The power supply of claim 1 , wherein the power switch comprises a relay switch and relay drive circuitry, wherein the relay switch is a single pull single throw (SPST) switch wherein power to said first power supply circuitry is interrupted when said SPST switch is open.

Claim 8

A power supply of a display apparatus having a universal serial bus hub, the power supply comprising: a rectifier for converting input AC voltage to output DC voltage; a display power management signaling power switch having an input and an output, said input of said display power management signaling power switch connected to the DC output of said rectifier; a pulse width modulation circuit having an input and an output, said input of said pulse width modulation circuit connected to said output of said display power management signaling power switch; a transformer having an input and an output, said input of said transformer connected to said output of said display power management signaling power switch, said output of said pulse width modulation circuit connected to said transformer; a power output circuit connected to said output of said transformer, output of said power output circuit being used to power a display of said display apparatus; an auxiliary power supply having an input and an output, said input of said auxiliary power supply being connected to said DC output of said rectifier; a microcontroller having horizontal and vertical synchronization signals as inputs and having said output of said auxiliary power supply as an input, said microcontroller producing a control signal as output which is used to control said display power management signaling power switch; and a DC to DC converter having an input and an output, said input of said DC to DC converter connected to said output of said auxiliary power supply and said output of said DC to DC converter connected to a universal serial bus hub.

Claim 9

A power supply of a display apparatus having a universal serial bus hub, the power supply comprising: a rectifier for converting input AC voltage to output DC voltage; a display power management signaling power switch having an input and an output, said input of said display power management signaling power switch connected to the DC output of said rectifier; a pulse width modulation circuit having an input and an output, said input of said pulse width modulation circuit connected to said output of said display power management signaling power switch; a transformer having an input and an output, said input of said transformer connected to said output of said display power management signaling power switch, said output of said pulse width modulation circuit connected to said transformer; a power output circuit connected to said output of said transformer, output of said power output circuit being used to power a display of said display apparatus; an auxiliary power supply having an input and an output, said input of said auxiliary power supply being connected to said DC output of said rectifier; a microcontroller having horizontal and vertical synchronization signals as inputs and having said output of said auxiliary power supply as an input, said microcontroller producing a control signal as output which is used to control said display power management signaling power switch; and a DC to DC converter having an input and an output, said input of said DC to DC converter connected to said output of said auxiliary power supply and said output of said DC to DC converter connected to a universal serial bus hub.

Claim 10

The power supply of claim 7 , wherein said display power management signaling power switch can be either in an open or a closed state, said display power management signaling power switch being in an open state only when both said horizontal and said vertical synchronization signals are in an inactive state, thus denying power to said pulse width modulation circuit, said transformer, said power output circuit and said display while power is continuously being delivered to said universal serial bus hub.

Claim 11

The power supply of claim 7 , wherein said display power management signaling power switch comprises: a bias resistor having a first end and a second end, said first end of said bias resistor connected to said control signal output of said microcontroller; a transistor having a base terminal, an emitter terminal, and a collector terminal, said emitter terminal being connected to electrical ground, said base terminal being connected to said second end of said bias resistor; a diode having a cathode and an anode, said anode connected to said collector terminal of said transistor and said cathode connected to said auxiliary power supply; a coil having a first end and a second end, said first end connected to said collector terminal of said transistor and said second end connected to said cathode of said diode; and a single pole single throw switch connected between said output of said rectifier and said input of said transformer, said single pole single throw switch being in the proximity of said coil allowing current in said coil to open and close said single pole single throw switch depending on the control signal output from said microcontroller.

Claim 14

The method of claim 10 , said first circuit comprising: a transformer having a first input and an output, said first input being connected to said power switch on a side of said power switch opposite said rectifier; a pulse width modulation circuit having an input and an output, said input being connected to said first input of said transformer and said output being electrically connected to a second input of said transformer; and an output circuit having an input connected to said output of said transformer, said output of said output circuit being electrically connected to said display device.

Claim 15

The method of claim 11 , said second circuit comprising: an auxiliary power supply having an input and an output, said input being electrically connected to said rectified DC power, said output being connected to said power switch and a microprocessor, said auxiliary power supply outputting a first DC voltage; and a DC/DC converter having an input and an output, said input being electrically connected to said output of said auxiliary power supply and said output being connected to said universal serial bus hub, said DC/DC converter receiving said first DC voltage and delivering a second DC voltage to said universal serial bus hub.