Patent ID: 8139169
Filing Date: 2012-03-20
Classification: G09G

Abstract:
1. A liquid crystal TV set, comprising: a tuner that receives a TV broadcast and extracts a TV broadcasting signal from the TV broadcast, and that output the TV broadcasting signal; a picture processor for displaying a picture on a liquid crystal display panel according to the TV broadcasting signal output from the tuner; a voice processor for outputting a voice from a speaker according to the TV broadcasting signal output from the tuner; a power supply circuit for supplying various types of supply voltages; a microcomputer for controlling an operation of the TV set; the TV set includes a sequence circuit for generating various types of voltages on the basis of various types of voltages output from the power supply circuit and supplying the generated voltages to the liquid crystal display panel in a predetermined sequence; the sequence circuit includes: a first output line for inputting a first input voltage and outputting the first input voltage to the liquid crystal display panel as a first output voltage; a first NPN type transistor having a base grounded through a capacitor and connected through a first resistor to a collector of the first transistor that inputs a second input voltage, the first transistor outputting a second output voltage to the liquid crystal display panel; an epitaxial planar NPN type second transistor having a grounded emitter, and turned on with inputting a first power-on-signal to a base of the second transistor and turned off with stopping input of the first power-on-signal to the base of the second transistor from the microcomputer, respectively; a first Zener diode having an anode connected to the emitter of the first transistor through a second resistor and a cathode connected to the collector of the second transistor through a third resistor; a PNP type third transistor having a base connected to the cathode of the Zener diode, and an emitter connected to the base of the third transistor through a fourth resistor and supplied a third input voltage; an NPN type fourth transistor having a base connected to the collector of the third transistor through a fifth resistor, an emitter grounded through a sixth resistor, and a collector being supplied a fourth input voltage through a seventh resistor; an NPN type fifth transistor having a base connected to the collector of the third transistor through the fifth resistor, an emitter grounded through the sixth resistor, a collector being supplied the fourth input voltage through the seventh resistor, and the fourth and fifth transistor outputting a third output voltage to the liquid crystal display panel; a second Zener diode having a cathode connected to the bases of the fourth and fifth transistors respectively and a grounded anode; an epitaxial planar NPN type sixth transistor having a grounded emitter and turned on with inputting a second power on signal to the base of the sixth epitaxial planar NPN type transistor and turned off with stopping the second power on signal to the base of the sixth epitaxial planar NPN type transistor from the microcomputer, respectively; a PNP type seventh transistor having a base connected to the collector of the sixth transistor and an emitter connected to the base of a seventh transistor through a eighth resistor and supplied the third input voltage; an NPN type eighth transistor having a collector connected to the emitter of the seventh transistor through a ninth resistor, a base connected to the collector of the seventh transistor through a tenth resistor, an emitter grounded through a eleventh resistor, the eighth transistor outputting a fourth output voltage to the liquid crystal display panel; and a third Zener diode having a cathode connected to the base of the eighth transistor and a grounded anode, the sequence circuit, when inputting the first, the second, the third and the fourth input voltages after the TV set is powered and the first power-on-signal is inputted, outputs the first output voltage as is at first; the second input voltage is applied to the collector of the first transistor, which is then self-biased and turned on to output the second output voltage; the second transistor is turned on with the first power-on-signal inputted to the base of the second transistor, thereby the third transistor is turned on, then the third, fourth, and fifth transistors are turned on and voltages supplied from the fourth input voltage line are lowered through the seventh resistor to be output as the third output voltage; finally, upon the turning-on of the sixth transistor with the second power-on-signal inputted later than the first power-on-signal, the seventh transistor is self-biased and turned on with the third input voltage applied to the emitter of the seventh transistor, so that the eighth transistor is turned on to output the fourth output voltage, thereby voltages are supplied to the liquid crystal TV set in the order corresponding to the first output voltage, the second output voltage, the third output voltage and the fourth output voltage; upon the turning-off of the power to the liquid crystal TV set, the first power-on-signal is stopped and the inputs of the first, the second, the third and the fourth input voltages to the sequence circuit are stopped; in the sequence circuit, the second-power-on signal inputted to the base of the sixth transistor is stopped, thereby the sixth transistor is turned off, then the seventh and eighth transistors are turned off to stop supply of the fourth output voltage to the liquid crystal display panel; the first power-on-signal is stopped and the second transistor is turned off, discharging of the remaining charge of the third input voltage inputted to the third transistor begins through the first Zener diode, and upon the lowering of the third input voltage to the break voltage of the first Zener diode, the first Zener diode stops breakdown and the third transistor is turned off to stop outputting the third output voltage; and finally, the first input voltage supply is stopped, thereby the first transistor is turned off and the second output voltage is stopped, thereby supply of voltages to the liquid crystal TV set are stopped in the order corresponding to the fourth output voltage, the third output voltage, the first output voltage and the second output voltage.