CIRCUIT AND MONITOR ENERGY SAVING METHOD BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a circuit and energy saving method of a monitor, and more particularly, to a circuit and method of energy saving of a device. monitor that can automatically turn off a monitor's main power source in accordance with various display power management signals (below, "DPM") when a computer is not operating for a predetermined period of time. Comments on the related technique Generally speaking, a monitor's energy-saving circuit automatically switches to an energy-saving mode in the case where a computer is not operating for a predetermined period of time, and then cuts off the supply of energy to the monitor until the user restarts the manipulation of the keys, in order to reduce unnecessary energy consumption. Monitors recently sold in the market adopt such energy saving function, but since the reliability between the monitor and the computer in the energy saving mode must be ensured in an essential way, the search for an improved quality of energy saving monitor continue until now.
Figure 1 is a block diagram illustrating the construction of a conventional monitor power supply circuit. As shown, under construction, the conventional monitor power supply circuit includes: an input power part 1 for decreasing the input power (AC) voltage; a noise filter 2 for inputting an output voltage of the input power part 1, if a main power supply switch SW1 is activated, in order to eliminate the noise in the output voltage; a part of rectification and flattening 3 to rectify and flatten the output voltage of the noise filter 2 by using a bridge diode BD1 and a capacitor Cl in order to convert the output voltage into a DC voltage Vd and to divide the DC voltage Vd by means of resistors R1 to R3 in order to produce the divided voltage; a power supply switching part 4 for producing a switching signal via the voltage divided VI of the rectifying and flattening part 3; and a voltage output part 5 for inducing the output of the rectifying and flattening part 3 to a secondary side of a transformer TI in accordance with the switching signal of the power supply switching part 4, for the purpose of thus producing a plurality of voltages (+ B1, + B2, + B3, ... ..) having different levels and an operating voltage to a monitor microcomputer. Here, a reference number "C2" indicates a capacitor. In the above construction, when the voltage of the input power (AC) decreases through the input part of the power supply 1, the main power supply switch SW1 is activated, and the noise filter 2 then sends the output voltage of the input part of energy 1 and eliminates the noise of power in order to send the noiseless voltage to the rectification and flattening part 3. At this time, the output voltage of the noise filter 2 is rectified by means of the bridge diode BD1 of the rectifying and flattening part 3 and then flattened by means of the capacitor Cl in the DC voltage Vd, in order to thereby send the DC voltage Vd to a primary side of the transformer TI of the output part of the energy 5. The DC voltage Vd is divided by means of the resistors Rl and R2 and the earth resistor R3 and is sent as divided voltage VI to the switching part of power supply 4 through the capacitor C2. When a switching resistor (not shown) in the power supply switching part 4 is repeatedly activated / deactivated, the DC voltage of the rectification and flattening part 3, which has been applied to the primary side of the transformer TI of the power supply output part 5, is induced to the secondary side of the CT transformer to be sent as a plurality of voltages which have different levels and as operating voltages of the monitor's microcomputer. The conventional monitor power supply circuit has, however, the following disadvantages: first, the power consumption is continuous unless the power supply of the monitor is turned off, in the case in which the computer is not operating, what does not prevent an unnecessary consumption of energy; and second, since the power supply continues even in the case in which the monitor is not used, the life of devices within the circuit is reduced, thus degrading the reliability of the power supply circuit. SUMMARY OF THE INVENTION Accordingly, the present invention focuses on a circuit and method of energy saving of a monitor that substantially eliminates one or more of the problems caused by the limitations and disadvantages of the related techniques. An object of the present invention is to provide a circuit and energy saving method of a monitor that can automatically turn off a main power supply and / or monitor heater power supply in accordance with various DPM signals, in the case of which a computer does not operate for a predetermined period of time, thus reducing the amount of energy consumed in the monitor. Another aspect of the present invention is to provide a circuit and energy saving method of a monitor that does not require any separate circuit construction arranged for the power supply to a microcomputer in an energy saving mode, thus reducing the cost of production. In accordance with one aspect of the present invention there is provided a power saving circuit of a monitor that includes: A power supply part for supplying a direct current (DC) power; a first transformation part for inputting the DC power in order to produce a plurality of different voltages; a second part of transformation to enter the DC power in order to supply in this way energy to a microcomputer, energy to a heater, and the operating energy of the first part of transformation; a microcomputer for determining a normal mode and an energy saving mode in accordance with a video signal of equipment connected to the monitor in order to thereby produce a control signal; a first energy saving part for controlling the operation of the first transformation part in accordance with the control signal of the microcomputer; and a second energy saving part for cutting off the heater energy from the second transformation part in accordance with the control signal of the microcomputer. In accordance with another aspect of the present invention, there is provided a method of energy saving of a monitor having a first transformation part for supplying various voltages and a second transformation part for supplying heater energy, comprising the steps of: If the input of a video signal proceeds from a computer, operate the first transformation part and the second transformation part; if the input of the video signal is not generated during a first period of time, suspend the operation of the first part of transformation; and if the input of the video signal is not generated during a second period of time, stop the heater energy. It will be understood that both the above general description and the detailed description that we present below are exemplary and provide an explanation of the claimed invention. BRIEF DESCRIPTION OF THE APPENDIX DRAWINGS The accompanying drawings, which are included to provide a further understanding of the present invention and are incorporated in and constitute a part of said specification, illustrate embodiments of the invention and together with the description serve to explain the principles. In the drawings: Figure 1 is a block diagram illustrating the construction of a conventional monitor power circuit; Figure 2 is a block diagram illustrating a power saving circuit of a monitor in accordance with the present invention; Figure 3 is a detailed circuit diagram illustrating the main parts of Figure 2; Figure 4 is an exemplary diagram illustrating the voltage output state by modes of operation in Figure 2; and Figure 5 is a flow chart illustrating an operating order of the monitor's energy saving circuit in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED MODALITY Reference will now be made to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Figure 2 is a block diagram illustrating a power saving circuit of a monitor in accordance with the present invention, and Figure 3 is a detailed circuit diagram illustrating the main parts of Figure 2. First the circuit of Monitor power saving in accordance with the present invention includes: a power supply part 20 for supplying a direct current (DC) power; a first transformation part 30 for inputting the DC power in order to produce a plurality of different voltages; a second transformation part 40 for inputting the DC power in order to thus supply the received DC energy as microcomputer energy, heater energy, and the operation energy of the first transformation part 30; a microcomputer 18 for determining the normal mode and a power saving mode in accordance with a video signal of equipment connected to the monitor in order to produce a control signal; a first energy saving part 14 (a first power switching part) for controlling the operation of the first transformation part 30 in accordance with the control signal of the microcomputer 18; and a second energy saving part 16 (a switching part for cutting off the heater energy produced from the second transformation part 40 in accordance with the control signal of the microcomputer 18. In more detail, the saving circuit The monitor power of the present invention comprises: a rectifier 11 for rectifying and flattening the AC power (AC 100-220 B) input in order to produce a DC voltage, a power factor controller 12 to compensate for a factor of power of the DC voltage in order to produce the compensated voltage as the initial operating voltages of a main power controller and a sub-power controller and to apply to a primary side coil of each of the main transformer TI and subtransformer T2; main transformer TI to input the DC voltage produced by the power factor controller 12 into the primary side coil of the same in order to produce the various different voltages (+ B1, + B2, + B3, + B4, ...) in accordance with the winding ratio of the coil; the main power controller 13 for controlling the operation of the main transformer TI with the DC voltage of the power factor controller 12 as the initial operating power; the transformer T2 to input the DC voltage produced by the power factor controller 12 in the primary side coil thereof in order to send the microcomputer energy and the heater energy through the secondary side coil thereof and to induce the voltage of the secondary side coil to produce the operating voltage of the main power controller 13 and the sub-power controller 15; the underfeeding controller 15 for inputting the initial operating voltage from the power factor controller 12 in order to thereby control the operation of the TI subtransformer; a sub-power switching part 17 for rectifying and flattening the output voltage of the sub-transformer T2 in order to supply the rectified and flattened DC energy as the operating voltage Vcc of the sub-power controller 15 by means of an external control signal; the microcomputer 18 for controlling the overall power circuit and for sending a first DPM control signal and a second DPM control signal in a power saving mode in accordance with the existence / non-existence of the video signal (synchronization signals horizontal / vertical) entered from the computer; the switching part 16 for activating / deactivating the heater energy sent from the transformer T2 in accordance with the first DPM control signal of the same computer 18; and the main power switching part 14 for inputting the energy of the subtransformer T2 in order to supply the operating voltage of the main power controller 13 in accordance with the second DPM control signal of the microcomputer 18 is being formed or cut. In this case, each of the main power controller 13 and the sub-power controller 15 includes a switching mode power supply (SMPS) function to induce the DC voltage applied to the primary side coil of each transformer TI and T2 to the secondary lateral bovine thereof. Figure 3 is a detailed circuit diagram illustrating the main parts of Figure 2. In more detail, the main transformer TI sends the plurality of different voltages in accordance with the winding ratio of the secondary side coil, where it is installed an integrated circuit 19 of constant voltage to send a voltage of 12B. Subtransformer T2 inputs the DC voltage provided by the power factor controller 12 in the primary side coil thereof in order to send the microcomputer + B7 energy and the heater + B7 energy through the secondary side coil thereof and to induce the voltage of the secondary side coil to produce the operating voltage Vcc of the main power controller 13 and the sub-power controller 15. Accordingly, the sub-power switching part 17 consists of a diode D2, a capacitor C3, and a photocoupler (a light emitting diode PD1 and a light receiving transistor PT1). If the microcomputer + B7 power comes from the subtransformer T2, the light emitting diode PD1 is operated to activate the light receiving transistor PT1, so that the operating voltage of the sub-power controller 15 can be supplied continuously. The main power switching part 14 is constituted by a DI diode and a capacitor Cl and includes a rectifier and smoother 14 (a) to rectify and flatten the output voltage of the subtransformer T2, a switch 14 (b) comprising a light emitting diode PD2, a light receiving transistor PT2, resistors R2, R3, R4 and a switching transistor Q1 and for supplying the DC voltage of the rectifier and smoother 14 (a) as operating voltage Vcc of the main power controller 13 in accordance with the output signal of the microcomputer 18, and a stabilizer 14 (c) comprising a capacitor C2 and a Zener diode, ZD1 and to stabilize the output power of the commutator 14 (b). In this case, the switching transistor Ql is a PNP transistor. In the aforementioned construction, an explanation of the operational effect of the monitor power saving circuit of the present invention will be discussed with reference to FIGS. 4 and 5. FIG. 4 is an exemplary diagram illustrating the voltage output state by modes of operation in Figure 2, and Figure 5 is a flow chart illustrating an order of operation of a power saving circuit of the monitor of
i according to the present invention. In the case in which the computer is not used by a user, that is, if the horizontal and vertical synchronization signals are not input to the monitor, the microcomputer 18 determines the status as the energy saving mode. On the contrary, if synchronization signals are input, the microcomputer determines the status as a normal mode. In other words, in step SI, the microcomputer 18 determines whether horizontal and vertical synchronization signals are input from the computer, and if detected in step S2, the state is determined as the normal mode in step S3. . However, if horizontal and vertical synchronization signals are not detected in step S2, the microcomputer 18 counts a predetermined period of time in step S4, and if it is not detected for a predetermined period of time TI in step S5, it is goes into a standby mode in step S6. In the standby mode, the microcomputer 18 executes the counting operation and if the synchronization signals are not detected for a predetermined time T2 in step S7, a disconnected mode is continued in step S8. At this time, the control by the normal, standby and off modes is illustrated in figure 4. In more detail, in the normal mode, the first DPM control signal DPMI and the second control signal DPM2 are produced in the logic station. "high", in the standby mode, the second DPM2 DPM2 control signal is produced in the "low" logic state, and in the off mode the first DPM DPMI control signal and the second DPM2 DPM control signal are produced in the logical state "low". Under the control of the microcomputer 18, now, an explanation of each part of the monitor power saving circuit will be presented. First, the input AC power is rectified and flattened in the DC voltage through a rectifier 11, and the DC voltage is compensated by power factor through the power factor controller 12 for its application to the main transformer TI and the subtransformer T2 and as initial voltage to the main power controller 13 and the sub-power controller 15, respectively. Then the main transformer TI is operated under the control of the main power controller 13 to thereby produce the various different voltages + Bi, B2, On the other hand, the subtransformer T2 changes the voltage of the power factor controller 12 through the sub-feeding controller 15 in order to thus produce the microcomputer + B7 energy and the heater + B8 power and the operating voltage Vcc of the main power controller 13 and the sub-power controller 15. At this time, in the normal mode , the microcomputer 18 sends the first DPM control signal and the second DPM control signal at the "high" logic level. As a result, the switching part 16 supplies the heater + B8 power from the subtransformer T2 to the heater in response to the first DPM control signal, and the main power switching part 14 operates the light emitting diode (PD2 in response). to the second control signal PDM, in order to activate the light-receiving transistor PT2, in this way, a polarized current is supplied to the base of the switching transistor Q1 in order to activate the switching transistor Q1. Accordingly, the DC voltage from the rectifier and smoother 14 (a) is applied to the main power controller 13, such that the main transformer TI produces a plurality of voltages and power supply + Bi, + B2, + B3, + B4, + B5, -B6 in accordance with the switching operation of the main power controller 13. During the previous process, if the horizontal synchronization signals and v erticales are not entered during the predetermined period of time from the computer, the microcomputer 18 determines the status as in standby mode.
In the standby mode, the microcomputer 18 sends the first DPM control signal at the "high" logic level and the second DPM control signal at the "low" logic level, respectively. As a result, the switching part 16 continuously supplies the heater + B8 power to a first DPM control signal, and the main power switching part 14 does not operate the light emitting diode PD2, in order to turn off in this way the light transistor PD2. Thus, the polarized current is not supplied to the base of the switching transistor Q1 in order to turn off the switching transistor Q1 in this way. Accordingly, the operation energy Vcc is not supplied to the main power controller 13, such that the main power controller 13 does not execute the switching operation to operate the main transformer TI, and therefore does not generate any voltage output on the secondary side of the main CT transformer. During the above process, if the horizontal and vertical synchronization signals are not entered in the predetermined time period from the computer, the microcomputer 18 determines that the state is in the off mode. In the off mode, the microcomputer 18 sends the first PDM control signal and the second PDM control signal at the "low" logic level. As a result, the switching part 16 cuts off the power supply of the heater + B8 in response to the first control signal PDM, and the main power switching part 14 does not operate the light emitting diode PD2, in order to turn off the transistor PT2 light receiver. In this way, the polarized current is not supplied to the base of the switching transistor Ql in order to turn off the switching transistor Ql. Accordingly, the operation energy Vcc does not supply the main power controller 13, such that the main power controller 13 does not execute the switching operation to operate the main transformer TI, and therefore no voltage output is generated on the secondary side of the TI transformer. At this point, independently of the PDM control signal the underfeed controller 15 operates the subtransformer T2. In other words, since the light-emitting diode PD1 of the underfeed switching part 15 is operated, the operating energy Vcc is continuously supplied to the underfeed controller 15, and the subtransformer T2 sends the microcomputer + B7 energy to avoid in this way the shutdown of the energy circuit. As mentioned above, a monitor energy saving circuit and method of the present invention have the following advantages: First, the energy consumption can be reduced due to a selective output of the heater energy; Second, no separate circuit is required to obtain the operating power of the microcomputer which thus reduces the production cost, since the subtransformer continuously supplies the operating power for the microcomputer even when it is in the power saving mode. Energy; and Third, due to the cut off of the heater power, the 3W norm can be met in the energy saving mode in the 2,000 power ultrapower saving standard required in the international standard and a USB function is added (bus in universal series). Accordingly, since the monitor power saving circuit of the present invention requires the design change in accordance with the size and standard of the product, numerous modifications and variations will be made without departing from the spirit or scope of the present invention. . Thus, the present invention covers the modifications and variations of this invention provided they fall within the scope of the appended claims and their equivalents.