KR19990014512U

KR19990014512U - Heater heating device of cathode ray tube

Info

Publication number: KR19990014512U
Application number: KR2019970027673U
Authority: KR
Inventors: 방정호
Original assignee: 윤종용; 삼성전자 주식회사
Priority date: 1997-10-06
Filing date: 1997-10-06
Publication date: 1999-05-06

Abstract

본 고안은 음국선관의 히터를 신속히 가열시켜 음극선관을 정상동작시키는 음극선관의 히터가열장치에 관한 것이다.The present invention relates to a heater heating apparatus of a cathode ray tube for rapidly heating the heater of the sound line tube.

본 고안의 음극선관의 히터가열장치(10)는 전자빔을 방출하기 위한 히터(H)를 구비한 음극선관(11), 교류전원을 수신하여 직류전원의 히터공급전압(Vp)을 출력하는 전압발생부(12), 음극선관(11)의 전원스위치가 온 되거나 파워오프모드의 해제시 기준시간 동안 활성화된 스위칭제어신호(SC)를 출력하는 제어신호발생부(13), 제어신호발생부(13)의 출력인 스위칭제어신호(SC)가 활성화되면 온되는 스위칭부(Q1) 및 히터공급전압(Vp)을 수신하여 스위칭부(Q1)가 온되면 제1전압을 갖는 히터가열전압(Vh)을 출력하고 스위칭부(Q1)가 오프되면 제1전압보다 작은 제2전압을 갖는 히터가열전압(Vh)을 출력하여 히터가열전압으로 히터(H)를 가열시키는 정전압발생부(20)로 구성된다.The heater heating device 10 of the cathode ray tube according to the present invention includes a cathode ray tube 11 having a heater H for emitting an electron beam, and a voltage generation for receiving an AC power and outputting a heater supply voltage Vp of a DC power source. A control signal generator 13 and a control signal generator 13 for outputting a switching control signal SC activated during a reference time when the power switch of the cathode ray tube 11 is turned on or released from the power-off mode. Receives the switching unit Q1 and the heater supply voltage Vp that are turned on when the switching control signal SC, which is an output of the control unit, is activated. When the switching unit Q1 is turned on, the heater heating voltage Vh having the first voltage is received. When the output unit is turned off and the switching unit Q1 is turned off, the heater heating voltage Vh having a second voltage smaller than the first voltage is output, and the constant voltage generator 20 is configured to heat the heater H to the heater heating voltage.

본 고안은 음극선관의 히터가열장치로 전원스위치가 온 되거나 파워오프모드의 해제된후 높은 전압을 갖는 히터가열전압에 의하여 히터를 가열시키므로서, 짧은 시간에 히터를 가열시킬 수 있고 음극선관의 정상동작 시간을 단축시킬 수 있으며, 음극선관의 표시부인 화면에 영상을 신속하게 나타낼 수 있다.The present invention heats the heater by a heater heating voltage having a high voltage after the power switch is turned on or the power-off mode is released by the heater heating device of the cathode ray tube, so that the heater can be heated in a short time and the top of the cathode ray tube is normal. The operation time can be shortened, and an image can be quickly displayed on a screen which is a display unit of a cathode ray tube.

Description

Heater heating device of cathode ray tube

본 고안은 음극선관의 히터가열장치에 관한 것으로, 특히 음국선관의 히터를 신속히 가열시켜 음극선관을 정상동작시키는 음극선관의 히터가열장치에 관한 것이다.The present invention relates to a heater heating device of the cathode ray tube, and more particularly to a heater heating device of the cathode ray tube to heat the cathode of the cathode ray tube quickly to operate the cathode ray tube normally.

음극선관(Cathode Ray Tube;CRT)은 전기신호를 전자빔의 작용으로 광학상으로 변환하여 화면에 표시하는 것으로, 음극선관은 음극선관의 히터(Heater)를 가열시켜 전자빔을 방출시킨다. 음극선관의 전원 스위치를 온 시킨 후 일정시간, 예를들어 6∼7초 정도의 시간동안 음극선관의 히터를 가열시켜야만 음극선관은 정상적으로 전자빔을 방출시켜 음극선관의 표시부인 화면에 영상이 나타난다.A cathode ray tube (CRT) converts an electric signal into an optical image by the action of an electron beam and displays it on a screen. The cathode ray tube emits an electron beam by heating a heater of the cathode ray tube. After the power switch of the cathode ray tube is turned on, the heater of the cathode ray tube must be heated for a predetermined time, for example, about 6 to 7 seconds, and the cathode ray tube normally emits an electron beam, so that an image is displayed on the screen of the cathode ray tube.

도 1은 종래의 음극선관의 히터가열장치의 블럭도이다.1 is a block diagram of a heater heating apparatus of a conventional cathode ray tube.

도 1의 히터가열장치(1)는 전자빔을 방출하기 위한 히터(H)를 구비한 음극선관(2), 교류전원을 수신하여 직류전원으로 출력하는 정류부 및 정류부의 직류전원을 수신하여 히터공급전압(Vp)을 출력하는 전압발생부(3) 및 히터공급전압(Vp)을 수신하여 일정한 전압의 히터가열전압(Vh)을 출력하여 히터가열전압(Vh)에 의하여 히터(H)를 가열시키는 정전압발생부(4)로 구성된다.The heater heating device 1 of FIG. 1 includes a cathode ray tube 2 having a heater H for emitting an electron beam, a rectifying unit for receiving AC power and outputting the DC power, and receiving the DC power of the rectifying unit to supply a heater supply voltage. A constant voltage for heating the heater H by the heater heating voltage Vh by receiving the voltage generator 3 outputting Vp and the heater supply voltage Vp and outputting a heater heating voltage Vh of a constant voltage. It consists of the generation part 4.

음극선관의 전력소모를 감소시키기 위하여 DPMS(Display Power Management Signalling) 모드를 실행하는 음극선관인 경우 수평 및 수직동기신호가 발생하지 않는 경우, 즉 파워오프모드의 경우 전압발생부(3)의 히터공급전압(Vp)은 출력되지 않으며, 수평 및 수직동기신호가 발생하면 파워오프모드는 해제되어 전압발생부(3)는 히터공급전압(Vp)을 출력한다.In the case of the cathode ray tube which executes the Display Power Management Signaling (DPMS) mode to reduce the power consumption of the cathode ray tube, when the horizontal and vertical synchronization signals do not occur, that is, in the power-off mode, the heater supply voltage of the voltage generator 3 Vp is not outputted, and when the horizontal and vertical synchronization signals are generated, the power-off mode is released, and the voltage generator 3 outputs the heater supply voltage Vp.

도 1의 종래의 히터가열장치(1)에 있어서, 전압발생부(3)는 음극선관(2)의 전원스위치가 온되거나 파워오프모드의 해제시 약 8V의 전압을 갖는 히터공급전압(Vp)을 출력하고, 정전압발생부(4)는 약 6.3V의 일정전압을 갖는 히터가열전압(Vh)을 출력하며, 히터가열전압(Vh)에 의하여 음극선관(2)의 히터(H)는 가열되고, 히터(H) 가열후 일정시간, 즉 히터 가열시간 경과후 음극선관은 전자빔을 방출하기 시작하여 정상동작을 한다.In the conventional heater heating device 1 of FIG. 1, the voltage generator 3 has a heater supply voltage Vp having a voltage of about 8 V when the power switch of the cathode ray tube 2 is turned on or the power off mode is released. , And the constant voltage generator 4 outputs a heater heating voltage Vh having a constant voltage of about 6.3 V, and the heater H of the cathode ray tube 2 is heated by the heater heating voltage Vh. After a certain time after heating the heater H, the cathode ray tube starts to emit an electron beam and operates normally.

종래의 음극선관의 히터가열장치는 음극선관의 전원스위치가 온 되거나 파워오프모드의 해제된후 히터가열전압은 일정하므로 음극선관이 정상동작 하기 위하여 장시간의 히터 가열시간이 필요하며, 이로인해 음극선관의 표시부인 화면에 영상이나타나기까지 장시간이 소요되는 문제점을 가지고 있다.In the conventional heater heating device of the cathode ray tube, since the heater heating voltage is constant after the power switch of the cathode ray tube is turned on or released in the power-off mode, a long heater heating time is required for the cathode ray tube to operate normally. It has a problem that it takes a long time until the image appears on the screen that is the display unit.

본 고안의 목적은 전원스위치가 온 되거나 파워오프모드의 해제된후 높은 전압을 갖는 히터가열전압에 의하여 히터를 가열시키므로서, 짧은 시간에 히터를 가열시킬 수 있고 음극선관의 정상동작 시간을 단축시킬 수 있는 음극선관의 히터가열장치를 제공하는 데 있다.An object of the present invention is to heat the heater by a heater heating voltage having a high voltage after the power switch is turned on or off the power off mode, it is possible to heat the heater in a short time and shorten the normal operation time of the cathode ray tube It is to provide a heater heating device of the cathode ray tube.

도 1은 종래의 음극선관의 히터가열장치의 블록도,1 is a block diagram of a heater heating device of a conventional cathode ray tube;

도 2는 본 고안의 음극선관의 히터가열장치의 블록도이다2 is a block diagram of a heater heating device of a cathode ray tube of the present invention.

상기의 목적들을 달성하기 위하여 본 고안의 음극선관의 히터가열장치는 전자빔을 방출하기 위한 히터를 구비한 음극선관, 교류전원을 수신하여 직류전원의 히터공급전압을 출력하는 전압발생부, 음극선관의 전원스위치가 온 되거나 파워오프모드의 해제시 기준시간 동안 활성화된 스위칭제어신호를 출력하는 제어신호발생부, 제어신호발생부의 출력인 스위칭제어신호가 활성화되면 온되는 스위칭부 및 히터공급전압을 수신하여 스위칭부가 온되면 제1전압을 갖는 히터가열전압을 출력하고 스위칭부가 오프되면 제2전압을 갖는 히터가열전압을 출력하여 히터가열전압으로 히터를 가열시키는 정전압발생부를 구비한 것을 특징으로 한다.In order to achieve the above objects, the heater heating device of the cathode ray tube of the present invention includes a cathode ray tube having a heater for emitting an electron beam, a voltage generator for receiving an AC power and outputting a heater supply voltage of DC power, and a cathode ray tube. When the power switch is turned on or the power off mode is released, the control signal generating unit outputs the switching control signal activated during the reference time, and receives the switching unit and the heater supply voltage which is turned on when the switching control signal which is the output of the control signal generating unit is activated. And a constant voltage generator for outputting a heater heating voltage having a first voltage when the switching unit is turned on, and outputting a heater heating voltage having a second voltage when the switching unit is turned off, thereby heating the heater to the heater heating voltage.

제 1전압은 제 2전압보다 크고 히터공급전압보다 작다.The first voltage is greater than the second voltage and less than the heater supply voltage.

이하, 첨부된 도면을 참조하여 본 고안의 음극선관의 히터가열장치를 상세히 설명하고자 한다.Hereinafter, with reference to the accompanying drawings will be described in detail the heater heating device of the cathode ray tube of the present invention.

도2는 본 고안의 음극선관의 히터가열장치의 블록도이다. 본 고안의 음극선관의 히터가열장치(10)는 전자빔을 방출하기 위한 히터(H)를 구비한 음극선관(11), 교류전원을 수신하여 직류전원의 히터공급전압(Vp)을 출력하는 전압발생부(12), 음극선관(11)의 전원스위치가 온 되거나 파워오프모드의 해제시 기준시간 동안 활성화된 스위칭제어신호(SC)를 출력하는 제어신호발생부(13), 제어신호발생부(13)의 출력인 스위칭제어신호(SC)가 활성화되면 온되는 스위칭부(Q1) 및 히터공급전압(Vp)을 수신하여 스위칭부(Q1)가 온되면 제1전압을 갖는 히터가열전압(Vh)을 출력하고 스위칭부(Q1)가 오프되면 제1전압보다 작은 제2전압을 갖는 히터가열전압(Vh)을 출력하여 히터가열전압으로 히터(H)를 가열시키는 정전압발생부(20)로 구성된다.2 is a block diagram of a heater heating device of a cathode ray tube of the present invention. The heater heating device 10 of the cathode ray tube according to the present invention includes a cathode ray tube 11 having a heater H for emitting an electron beam, and a voltage generation for receiving an AC power and outputting a heater supply voltage Vp of a DC power source. A control signal generator 13 and a control signal generator 13 for outputting a switching control signal SC activated during a reference time when the power switch of the cathode ray tube 11 is turned on or released from the power-off mode. Receives the switching unit Q1 and the heater supply voltage Vp that are turned on when the switching control signal SC, which is an output of the control unit, is activated. When the switching unit Q1 is turned on, the heater heating voltage Vh having the first voltage is received. When the output unit is turned off and the switching unit Q1 is turned off, the heater heating voltage Vh having a second voltage smaller than the first voltage is output, and the constant voltage generator 20 is configured to heat the heater H to the heater heating voltage.

스위칭부(Q1)는 바이폴라 트랜지스터 또는 모스트랜지스터로 구성할 수 있다. 스위칭부(Q1)를 콜렉터단, 에미터단 및 베이스단을 갖는 제1트랜지스터로 구성하는 경우 에미터단은 접지접압(Vss)에 연결되고 베이스단은 스위칭제어신호(SC)와 연결되어 스위칭제어신호(SC)의 전압에 따라 콜렉터단의 전압은 접지전압(Vss) 이상의 전압을 출력한다.The switching unit Q1 may be configured as a bipolar transistor or a MOS transistor. When the switching unit Q1 is configured as a first transistor having a collector end, an emitter end, and a base end, the emitter end is connected to the ground contact voltage Vss, and the base end is connected to the switching control signal SC, so that the switching control signal ( According to the voltage of SC), the voltage at the collector stage outputs a voltage higher than the ground voltage Vss.

정전압발생부(20)는 에미터단은 히터공급전압(Vp)에 연결되고 베이스단은 제1트랜지스터(Q1)의 콜렉터단에 연결되고 콜렉터단은 히터(H)에 연결되어 히터가열전압(Vh)을 출력하는 제2트랜지스터(Q2), 제2트랜지스터(Q1)의 에미터단과 베이스단 사이에 바이어스전압을 인가시키기 위한 바이어스저항(Rb), 제1저항(R1) 및 제2저항(R2)으로 구성되어 히터가열전압(Vh)을 분배하여 분배전압(Vd)을 출력하는 분배부(21) 및 분배부(21)의 분배전압(Vd)에 따라 바이어스저항(Rb)에 흐르는 전류를 가변시키는 전류제어부(22)로 구성된다.The constant voltage generator 20 has an emitter end connected to a heater supply voltage Vp, a base end connected to a collector end of the first transistor Q1, and a collector end connected to a heater H, thereby heating a heater heating voltage Vh. The second transistor Q2, which outputs the voltage, and the bias resistor Rb, the first resistor R1 and the second resistor R2 for applying a bias voltage between the emitter terminal and the base terminal of the second transistor Q1. The current is configured to vary the current flowing through the bias resistor Rb in accordance with the distribution unit 21 and the distribution unit 21 for distributing the heater heating voltage Vh and outputting the distribution voltage Vd. It consists of a control unit 22.

상기의 구성에 따른 본 고안인 음극선관의 히터가열장치의 동작은 다음과 같다.Operation of the heater heating device of the cathode ray tube of the present invention according to the above configuration is as follows.

음극선관(11)의 전원스위치가 오프이거나 음극선관의 전력소모를 감소시키기 위하여 DPMS 모드를 실행하는 음극선관인 경우 파워오프모드일때 전압발생부(12)는 히터공급전압(Vp)을 출력하지 않으므로 음극선관(11)의 히터(H)는 가열되지 않는다. 음극선관(11)의 전원스위치가 온되거나 파워오프모드가 해제되면 전압발생부(12)는 약 8V의 히터공급전압(Vp)을 출력한다. 제어신호발생부(13)는 음극선관(11)의 전원스위치가 온 되거나 파워오프모드의 해제후 사용자가 정한 기준시간 동안 활성화된 스위칭제어신호(SC)를 출력한다. 제1트랜지스터(Q1)로 구성된 스위칭부는 스위칭제어신호(SC)가 활성화되면 온된다. 즉 활성화된 스위칭제어신호(SC)에 의하여 제1트랜지스터(Q1)의 콜렉터단의 전압은 제1트랜지스터의 콜렉터단과 에미터단간의 전압(VCE1)으로 접지전압(Vss)에 가까운 전압이 된다. 정전압발생부(20)의 제2트랜지스터(Q2)의 베이스단의 전압인 제1트랜지스터(Q1)의 콜렉터단의 전압은 낮은 전압을 가지므로 제2트랜지스터(Q2)는 온되고 이때 제2트랜지스터(Q2)에 흐르는 전류는 가장 크고 제2트랜지스터(Q2)의 콜렉터단과 에미터단간의 전압(VCE2)은 최소전압이 된다. 따라서 히터(H)를 가열시키기 위한 히터가열전압(Vh)은 히터공급전압(Vp)－제2트랜지스터(Q2)의 콜렉터단과 에미터단간의 전압(VCE2)이므로 히터가열전압(Vh)은 약 8V인 히터공급전압(Vp)보다 작으나 종래의 히터가열장치(1)의 히터가열전압인 약 6.3V 보다는 상당히 높은 제1전압을 가지므로 신속하게 음극선관의 히터(H)를 가열시킨다. 음극선관(11)의 전원스위치가 온 되거나 파워오프모드의 해제후 사용자가 정한 기준시간이 경과되면 제어신호발생부(13)의 스위칭제어신호(SC)는 비활성화되므로 스위칭부인 제1트랜지스터(Q1)는 오프된다. 제1트랜지스터(Q1)의 오프되면 제2트랜지스터(Q2)는 바이어스저항(Rb)에 의하여 제2트랜지스터(Q2)의 베이스단과 에미터단간의 바이어스전압에 의하여 제2트랜지스터(Q2)는 온되고 분배부(21)의 제1저항(R1)과 제2저항(R2)에 의하여 히터가열전압(Vh)을 분배하여 분배전압(Vd)를 출력한다. 분배전압(Vd)은 히터가열전압(Vh)이 클수록 높은 전압을 가진다. 전류제어부(22)는 분배부(21)의 분배전압(Vd)에 따라 바이어스저항(Rb)에 흐르는 전류를 가변시킨다. 예를들어 분배전압(Vd)이 사용자가 정해준 기준전압보다 크면 바이어스저항(Rb)에 흐르는 전류를 작게하여 제2트랜지스터(Q2)의 베이스단과 에미터단간의 바이어스전압을 작아지게 하여 히터가열전압(Vh)을 낮추어주고, 분배전압(Vd)이 기준전압보다 작으면 바이어스저항(Rb)에 흐르는 전류를 크게하여 제2트랜지스터(Q2)의 바이어스전압을 크게 하여 히터가열전압(Vh)은 높은 전압을 갖도록 하므로서 정전압발생부(20)는 일정한 제2전압, 약 6.3V의 기준전압을 갖는 히터가열전압(Vh)을 출력한다.When the power switch of the cathode ray tube 11 is turned off or the cathode ray tube executing DPMS mode to reduce power consumption of the cathode ray tube 11 is in the power off mode, the voltage generator 12 does not output the heater supply voltage Vp. The heater H of the pipe 11 is not heated. When the power switch of the cathode ray tube 11 is turned on or the power-off mode is released, the voltage generator 12 outputs a heater supply voltage Vp of about 8V. The control signal generator 13 outputs the switching control signal SC that is activated for a reference time set by the user after the power switch of the cathode ray tube 11 is turned on or the power off mode is released. The switching unit configured of the first transistor Q1 is turned on when the switching control signal SC is activated. That is, the voltage of the collector terminal of the first transistor Q1 becomes a voltage close to the ground voltage Vss as the voltage VCE1 between the collector terminal and the emitter terminal of the first transistor according to the activated switching control signal SC. Since the voltage at the collector terminal of the first transistor Q1, which is the voltage at the base terminal of the second transistor Q2 of the constant voltage generator 20, has a low voltage, the second transistor Q2 is turned on, and at this time, the second transistor Q2 is The current flowing in Q2) is the largest and the voltage VCE2 between the collector terminal and the emitter terminal of the second transistor Q2 becomes the minimum voltage. Therefore, since the heater heating voltage Vh for heating the heater H is the voltage between the collector and emitter terminals of the heater supply voltage Vp and the second transistor Q2, the heater heating voltage Vh is about 8V. The heater H of the cathode ray tube is rapidly heated since the first heater supply voltage Vp is smaller than the phosphorus supply voltage Vp but is considerably higher than about 6.3 V, which is the heater heating voltage of the conventional heater heating device 1. When the power switch of the cathode ray tube 11 is turned on or the user-defined reference time elapses after the power-off mode is released, the switching control signal SC of the control signal generator 13 is inactivated so that the first transistor Q1 is a switching unit. Is off. When the first transistor Q1 is turned off, the second transistor Q2 is turned on by the bias resistor Rb and the second transistor Q2 is turned on by the bias voltage between the base terminal and the emitter terminal of the second transistor Q2. The heater heating voltage Vh is distributed by the first resistor R1 and the second resistor R2 of the distribution unit 21 to output the distribution voltage Vd. The distribution voltage Vd has a higher voltage as the heater heating voltage Vh is larger. The current controller 22 varies the current flowing through the bias resistor Rb according to the distribution voltage Vd of the distribution unit 21. For example, when the distribution voltage Vd is greater than the reference voltage set by the user, the current flowing through the bias resistor Rb is made small so that the bias voltage between the base terminal and the emitter terminal of the second transistor Q2 is decreased, and thus the heater heating voltage ( When the voltage Vd is lower than the reference voltage, the current flowing through the bias resistor Rb is increased to increase the bias voltage of the second transistor Q2, and the heater heating voltage Vh is increased. The constant voltage generator 20 outputs a heater heating voltage Vh having a constant second voltage and a reference voltage of about 6.3V.

활성화될때의 스위칭제어신호(SC)의 전압에 따라 제1트랜지스터(Q1)의 콜렉터단의 전압은 접지전압 보다 큰 전압을 갖도록 할 수 있으나 제1트랜지스터(Q1)의 콜렉터단의 전압은 낮을수록 히터가열전압(Vh)은 큰 전압을 가지므로 히터(H)를 더 신속하게 가열시킬 수 있다.When the voltage of the collector terminal of the first transistor Q1 is greater than the ground voltage according to the voltage of the switching control signal SC when it is activated, the voltage of the collector terminal of the first transistor Q1 is lower. Since the heating voltage Vh has a large voltage, the heater H can be heated more quickly.

따라서 본 고안인 음극선관의 히터가열장치(10)는 음극선관(11)의 전원스위치가 온 되거나 파워오프모드의 해제후 사용자가 정한 기준시간 동안 활성화된 스위칭제어신호(SC)에 의하여 제1트랜지스터(Q1)는 온되고, 제1트랜지스터(Q1)의 온에 의해 제2트랜지스터(Q2)의 콜렉터단인 히터가열전압(Vh)은 최대의 전압인 제1전압을 출력하므로 음극선관(11)의 히터(H)는 신속히 가열되고 사용자가 정한 기준시간 경과후에는 제1트랜지스터(Q1)는 오프되고 정전압발생부(20)는 일정전압을 갖는 제2전압인 히터가열전압(Vh)을 출력한다.Therefore, the heater heating device 10 of the cathode ray tube according to the present invention has a first transistor by a switching control signal (SC) that is activated for a reference time determined by a user after the power switch of the cathode ray tube 11 is turned on or the power off mode is released. Q1 is turned on, and the heater heating voltage Vh, which is the collector end of the second transistor Q2, outputs the first voltage which is the maximum voltage by turning on the first transistor Q1. The heater H is rapidly heated, and after a reference time set by the user, the first transistor Q1 is turned off and the constant voltage generator 20 outputs a heater heating voltage Vh, which is a second voltage having a constant voltage.

Claims

In the heater heating device for heating the heater having a cathode ray tube having a heater for emitting an electron beam, a voltage generator for receiving an AC power and outputting a heater supply voltage of the DC power,

Control signal generating means for outputting a switching control signal activated during a reference time when the power switch of the cathode ray tube is turned on or the power off mode is released;

Switching means which is turned on when the switching control signal which is the output of the control signal generating means is activated; And

When the switching means is turned on to receive the heater supply voltage, the heater heating voltage having a first voltage is output. When the switching means is turned off, the heater heating voltage having a second voltage is output. And a constant voltage generating means for heating the heater.

The method of claim 1,

The switching means comprises a bipolar transistor having a collector stage, an emitter stage, and a base stage, wherein the emitter stage is connected to a ground voltage, and the base stage is connected to the switching control signal to perform the switching control signal. The heater heating device according to the voltage, characterized in that the voltage of the collector terminal outputs a voltage higher than the ground voltage.

The method of claim 1,

The switching means is a heater heating apparatus, characterized in that consisting of a morph transistor.

The method of claim 1,

Wherein said first voltage is greater than said second voltage and less than said heater supply voltage.

A first transistor having an emitter end, a base end, and a collector end, wherein the emitter end is connected to a ground voltage and the base end is connected to the switching control signal to be turned on when the switching control signal is activated; And

When the first transistor is turned on to receive the heater supply voltage, a heater heating voltage having a first voltage is output. When the first transistor is turned off, a heater heating voltage having a second voltage is output. And a constant voltage generating means for heating said heater at a heating voltage.

The method of claim 5,

The constant voltage generating means

An emitter stage, a base stage and a collector stage, wherein the emitter stage is connected to the heater supply voltage, the base stage is connected to the collector stage of the first transistor, and the collector stage is the heater A second transistor connected to the heater and outputting a heater heating voltage;

A bias resistor for applying a bias voltage between the emitter terminal and the base terminal of the second transistor;

Distribution means comprising a first resistor and a second resistor for distributing the heater heating voltage and outputting a divided voltage; And

And a current control means for varying a current flowing in the bias resistor in accordance with the distribution voltage of the distribution means.