baber/WOPTO huggingface dataset:
Patent KR-20000042905-A (KR)
Title: Method of managing connection for supporting hand-over in atm exchange system
Inventor: KIM YEONG JIN
IPC: H04L12/28
Filed: 1998-12-28
Abstract: PURPOSE: A method of managing connection for supporting a hand-over in an asynchronous transfer mode(ATM) exchange system is provided to prevent lowering of a call quality, which is caused by momentarily intercepting of a traffic channel to be generated in hand-over, when a cellular phone requests the ATM exchange system for setting up of a connection, and to enable of a soft hand-over for a lower link direction. CONSTITUTION: A method of managing connection for supporting a hand-over in an asynchronous transfer mode(ATM) exchange system contains processes. The first process is to set up a single directional point to multiple point connection, for a transmitting and incoming party port when requesting for setting up of a wireless connection, and to register multicast information according to the setup connection. The second process is newly to set up single direction and multi direction point connections, to a port to be handed over, and to register the multicast information additionally. The third process is to delete a connection setup before applying a hand-over and the multicast information, in ending hand-over.
Patent KR-20000047061-A (KR)
Title: Digital steel camera casing
Inventor: KIM YONG KI
IPC: H04N5/225
Filed: 1998-12-31
Abstract: PURPOSE: A digital steel camera casing is provided, which secures single space easily and is handy to carry by securing easily larger space to install a display and being folded. Also a display is controlled according to the position of a camera, thereby observing a display in a comfortable position. CONSTITUTION: A digital steel camera casing with built-in components such as an image pickup element (4), PCB, a memory comprises; a liquid crystal case (22) which has a display (14) to expose a screen of a display (14) and is combined with an opening and closing case (24) by assemblies for hinging; an opening and closing case (24)(26) which is combined to overlap together with a liquid crystal case (22); a lens case (28) on which a lens (2) is set.
Patent KR-19990044478-A (KR)
Title: 2-아실아미노벤즈아미드 유도체 및 혈관내막세포 과잉증식에 기인하는 질환의 예방 및 치료제
IPC: C07C259/10
Filed: 1996-08-29
Abstract: 본 발명은, 혈관내막세포과잉증식에 기인하는 질환의 예방 및 치료제로서 유용한, 화학식 I 
     (화학식 I) 
     
       
     
     (R 1 , R 2 , R 3 , R 4 , R 5 는 수소원자등, X는 비닐렌기등이고, B는 일반식 -N(R 6 )(R 7 ) (R 6 , R 7 은 수소원자등), -NH-(CH 2 ) n -A-R 8 (A는 단일결합등, R 8 은 수산기등), 또는 히드록시아미노기이다)로 표시되는 2-아실벤즈아미드 유도체에 관한 것이다.
Patent KR-19990067467-A (KR)
Title: 테이프 카트리지용 다중 드라이브 다중 매거진 대량 저장 및 검색 유니트
IPC: G11B15/68
Filed: 1996-11-04
Abstract: 본 발명은 복수의 테이프 카트리지 매거진 중 하나로부터, 복수의 테이프 드라이브중 선택된 하나로의 전달을 위해 복수의 테이프 카트리지중 선택된 하나를 자동으로 검색하는 테이프 카트리지용 다중 드라이브 다중 매거진 대량 저장 및 검색 유니트에 관한 것이다.  유니트는 또한 복수의 테이프 카트리지 매거진중 하나에서의 저장을 위해 복수의 테이프 드라이브중 하나로부터 복수의 테이프 카트리지 중 선택된 하나를 검색한다.  테이프 카트리지 승강기가 복수의 테이프 카트리지 매거진과 복수의 테이프 드라이브 사이에서 테이프 카트리지를 검색하고 운반한다.  유니트간 카트리지 운반 유니트가 복수의 테이프 저장 및 검색 유니트가 함게 결합되고 카트리지가 결합된 유니트들 사이를 자동으로 통과할 수 있게 한다.
Patent KR-19990087216-A (KR)
Title: 수면부유성 미생물 농약
IPC: A01N63/30
Filed: 1997-12-24
Abstract: 미생물과 W/O 타입의 계면활성제와 오일과 겉보기 비중이 작은 분체(粉體)를 함유하여 이루어지는 것을 특징으로 하는 수면부유성(水面浮遊性) 미생물농약과 이 농약을 무논에 산포하는 것을 특징으로 하는 수면부유성 미생물 농약의 사용방법 및 미생물을 물에 현탁하여 이 현탁액에 W/O 타입의 계면활성제를 함유하는 오일을 가하여 혼합하고, 여기에 겉보기 비중이 작은 분체를 가하여 미생물 농약을 제조하는 것을 특징으로 하는 상기 농약의 제조방법.
Patent KR-19990087217-A (KR)
Title: 디스크기판 성형용 금형과 그 제조방법 및 금형장치
IPC: G11B7/26
Filed: 1997-12-25
Abstract: 정보신호의 기록매체로 되는 디스크를 구성하는 디스크기판을 성형하기 위한 디스크기판 성형용의 금형이다.  이 금형은, 디스크기판의 성형면측이 소정의 두께로 연마된 금형모재를 가지고, 이 금형모재의 연마된 성형면상에 표면이 연마된 금속막이 소정의 두께로 성막되어 있다.  금속막은, 금형모재의 디스크기판의 성형면상에, 300g 이상의 부착강도로 성막됨으로써, 연마시나 디스크기판의 성형시에 모재로부터의 박리가 방지된다.  이 금속막에는, 성형되는 디스크기판에 형성되는 요철이나 돌출형부나 요형부로 이루어지는 피트패턴에 대응하도록 패턴이 에칭에 의해 형성되어 있다.
Patent KR-20000016683-A (KR)
Title: Communications webs for pstn subscribers
Inventor: SNELLING RICHARD K
IPC: H04M1/715
Filed: 1998-03-04
Abstract: PURPOSE: Systems are provided for connecting a telecommunications infrastructure line (640) to a plurality of telephones, handsets (300), computers, a telecopy machine (400) and other end user interfaces or consumer electronics devices in a residence or business. CONSTITUTION: Systems includes a Network Control Unit (100) which form the center of a star topology and which communicate via RF link with a Wireless Access Unit (200) and handsets. Wireless Access Units feature an interface, such as, for example, a standard telephone jack, for accommodating a telephone, a fax machine, a compute modem or other device. Computers or other devices may also be accommodated by Wireless Access Units having other physical and virtual interfaces, including, for instance, serial ports or network interfaces. The Wireless Access Units may also be digital to accommodate ISDN or any other digital standard. Wireless control/monitoring accessories may also be employed to communicate with the Network Control Unit and provide additional functionality such as entrance monitoring, baby monitoring, HVAC control and other services.
Patent KR-20000050709-A (KR)
Inventor: JI SEON GU
IPC: F04D29/38
Filed: 1999-01-14
Abstract: PURPOSE: An indoor unit of an air conditioner is provided to guide the air flowing into a ventilator with plural blades by mounting a guide unit on the case of ventilator. CONSTITUTION: A ventilator(10) rotates with a motor and external air flows into a body through an air inlet on the lower part of body. The air is introduced into plural blades(13) through opening holes of a case(4) and then guided to plural guide blades fixed to the case. After changing the direction with the guide blades, the air is reflected from the blades, sprayed to the upper part of ventilator and discharged to outside through an outlet of body.
Patent KR-20000051259-A (KR)
Title: A safety device of secondary battery
Inventor: HONG EU SUN
IPC: H01M2/12
Filed: 1999-01-20
Abstract: PURPOSE: A safety means for a secondary battery is provided to produce the same safety effect as conventional devices thereof without a laser welding by emitting inside gas to the outside when internal pressure of a battery increases. CONSTITUTION: A through hole is formed on a cap assembly (24) or a can (20), and a plug (36) is put in the through hole (36). Diameter of the through hole (36) is 2.0 to 2.2mm and external diameter of the plug (38) is more than 2.2mm. A tolerance limit of the plug (38) is 0.005 to 0.01mm. Electrolyte is injected into the through hole (36). The safety means for a secondary battery in accordance with the present invention is provided to increase frictional force between external circumstance of the plug and internal circumstance of the through hole by forming the through hole on a cap assembly or a can and forcibly putting the plug in, where diameter of the plug is a little bit larger than the through hole thereof. And the safety means in accordance with the present invention is also provided to obtain a safety by emitting inside gas upon battery disorder. Further another object of the present invention is to eliminate factors of charge raise due to a laser welding and to improve reliance on the product by minimizing defective proportion of the safety means.
Patent KR-20000051549-A (KR)
Title: Deflection yoke
Inventor: KIM JAE JEONG
IPC: H01J29/76
Filed: 1999-01-23
Abstract: PURPOSE: A deflection yoke is provided to improve reliability of a cathode ray tube using the deflection yoke by beforehand preventing noise generated by a minute vibration that occurs when an inner arm operates to form a ferromagnetic field. CONSTITUTION: A deflection yoke comprises a coil separator(21), a vertical deflection coil, a ferrite core, an inner arm(25) and a soundproofing element. A horizontal coil forming a horizontal deflection magnetic field is established inside the coil separator and a coupling groove having a predetermined width is formed on an intermediate both sides of an external surface along a circumferential direction. The vertical deflection coil forms a vertical deflection magnetic field, established on an external surface of the coil separator. The ferrite core is established on the coil separator to intensify the vertical deflection magnetic field by the vertical deflection coil. The inner arm barrel-magnetizes the vertical deflection magnetic field through the vertical deflection coil, inserted into the coupling groove of the coil separator. The soundproofing element absorbs the noise caused by the vibration of the inner arm generated in the course of the barrel-magnetization of the vertical deflection magnetization through the inner arm, established on the coil separator adjacent to the portion to which the inner arm is coupled.
Patent KR-20000055577-A (KR)
Inventor: BAEK SANG GYUN
IPC: F24F1/02
Filed: 1999-02-08
Abstract: PURPOSE: An apparatus for coupling an air guide with a shroud of a window type air conditioner is provided to prevent noise due to air flow and air leakage by smoothly circulating the air in the air guide by changing the structure of the apparatus for coupling the air guide with the shroud, and improve the strength of the air conditioner by firmly coupling the air guide with the shroud. CONSTITUTION: In an apparatus for coupling an air guide with a shroud of a window type air conditioner including an air guide mounted in an indoor unit cabinet for guiding suction air to a discharge hole via an indoor heat exchanger, a supporting die formed at a rear upper part of the air guide, and a shroud(14) mounted in an outdoor unit for guiding suction air to an outdoor heat exchanger, the supporting die is formed with a plurality of coupling grooves(106) and coupling parts(107) at an end part, and the shroud is formed with a coupling protrusion(109) at a front upper part to be coupled with a screw in accordance with a plurality of insertion protrusions(108) to be inserted into the coupling grooves and the coupling parts.
Patent KR-19990077410-A (KR)
IPC: G02F1/1333
Filed: 1999-02-08
Abstract: 평탄한 광 반사면을 가지며, 회절에 의한 반사광의 손실이 적은 반사형 액정 소자, 그의 제조 방법 및 이러한 액정 소자를 이용한 프로젝션 표시 장치를 제공한다. 
     액티브 매트릭스형의 반사형 액정 소자는, 화소에 대응하여 설치된 스위칭 소자 및 스위칭 소자에 접속된 화소 전극(32)의 배열을 갖는 어레이 기판과, 액정층을 끼워서 화소 전극(32)의 배열과 대향하는 투명 전극을 갖는 대향 기판을 포함한다.  각 화소 전극(32)은 전극 스터드(electrode stud), 즉 분할 전극(68)의 배열을 갖도록 형성된다.  스터드(68) 간의 영역은 절연재(64)로 매립되어 있다.  스터드 배열의 표면은 화학 기계적인 연마 처리에 의해 평탄해진다.  스터드 배열의 평탄한 표면 상에 유전체 광 반사막이 설치되며, 그 위에 액정 분자 배향막이 설치된다.
Patent KR-19990046335-A (KR)
Title: 아이스크림의조성물
Filed: 1999-02-12
Abstract: 본 발명은 아이스크림의 조성물에 관한 것으로서, 이미 공지되어 만들어지고 있는 아이스크림의 조성물 유지방,아이스밀크, 유크림,탈지분유,정맥당, 백설탕 의 조성물에 감(甘)을 숙성하여 연시화 한것과, 포도를 발효, 숙성하여 알콜도수가 10도 이상인 포도의 엑기스를 첨가하여 만들어진 아이스크림의 조성물에 그 특징이 있는 아이스크림의 조성물.
Patent KR-20000059814-A (KR)
Inventor: NAM GI HYEON
IPC: C08J7/04
Filed: 1999-03-09
Abstract: PURPOSE: A method for preparing the release film for water-based slurry is provided, to improve the adhesion between a release layer and water slurry and the size stability land to lower the delamination. CONSTITUTION: The method comprises the steps of mixing 100 parts by weight of a silicone resin, a curing agent, 2-20 parts by weight of colloidal silica, 0-20 parts by weight of a silane coupling agent for improving the dispersity of the silica and a solvent to prepare a silicone coating solution; coating a polyester film with a silane coupling agent or the mixture of a 100 parts by weight of silane coupling agent and 75 parts by weight of polyester copolymer or less, to form primer coating layer; coating the film with the silicone coating solution; and curing the film to obtain a release film.
Patent KR-20000060269-A (KR)
Inventor: KANG HO SUL
IPC: F25D11/00
Filed: 1999-03-13
Abstract: PURPOSE: A Kimchi refrigerator is provided to sufficiently secure the efficiency of the insulation of each chamber, easily assemble a barrier, and equally supply cool air. CONSTITUTION: A Kimchi refrigerator includes protrusion parts(54) inwardly protrusively formed from the both side walls(52) of a main body at a regular gap, and a barrier(60) mounted between the protrusion parts for dividing the inside of the refrigerator into a first chamber(50) and a second chamber(70), so that a break is not generated between the both side walls and the barrier. The corner of the both side walls wherein the protrusion parts are formed is rounded and a duct is formed in the inside of the barrier for passing by cool air supplied or returned.
Patent KR-20000060501-A (KR)
Inventor: KWAK DONG YEONG
IPC: G02F1/1333
Filed: 1999-03-16
Abstract: PURPOSE: A liquid crystal display is provided to improve a corrosion proof and an impact-proof of the liquid crystal display can be enhanced by arranging corner cutting keys for cutting the corner or forming a vernier for grinding the corner part. CONSTITUTION: The liquid crystal display includes a corner cutting key for cutting the corner of the liquid crystal display. At this time, first and second corner cutting keys(40a,40b), which are adjacent with each other, are arranged to the corner of the liquid crystal display in order to make a corrosion-proof of the liquid crystal display enhance. A boundary point having a predetermined distance(for example, 0.2mm) at the lower part of the first corner cutting key(40a) and a boundary point having a predetermined distance(for example, 0.2mm) at the upper part of the second corner cutting key(40b) are connected with each other. Therefore, a distance(for example, 0.4mm) exists between the first and second corner cutting keys(40a,40b).
Patent KR-20000061850-A (KR)
Inventor: PARK UI GWON
IPC: H04B1/40
Filed: 1999-03-31
Abstract: PURPOSE: A method for displaying current time is provided to display current time to users regardless of present locations of the users, by using a real-time reference clock to produce the current time when the users are in service-interrupted areas. CONSTITUTION: A radio frequency(RF) receiver receives information on current time from a base station, and outputs the information to a controller. The controller produces current time and outputs a control signal for displaying the produced current time to a liquid crystal display(LCD) panel. The LCD panel displays the current time to a user. The controller decides whether the user is in a servicing area. If so, the controller performs a normal displaying operation. If the user is not in the servicing area, the controller receives a real-time reference clock from a real-time clock transmitter to count the reference clock, and produces current time to output a control signal for displaying the current time to the LCD panel. The LCD panel displays the current time to the user, and decides whether another user is in a servicing area.
Patent KR-20000066385-A (KR)
Inventor: PARK GI HONG
IPC: G11C11/407
Filed: 1999-04-16
Abstract: PURPOSE: An apparatus for equalizing a local data bus line is provided to realize the high speed operation by improving the driving ability of a bit line sense amp. CONSTITUTION: A semiconductor memory device includes a bit line sense amp sensing and amplifying data stored in a cell during read operation and outputting it to a bit line, a first pass transistor(1) which outputs the amplified data of the bit line to a local data bus line, being turned on by a local column decoding signal, and a second pass transistor(5) which outputting the amplified data of the local data bus line to a global data bus line, being turned on by a pass transistor gate signal(L2G-U,L2G-D). An apparatus for equalizing the local data bus line improves the driving ability of a bit line sense amp by equalizing the local data bus line before next column operation after read operation by comprising a connection unit between local data bus lines. The apparatus comprises: a unit generating the pass transistor gate signal by receiving a column bank selection signal and a column address signal, and a local data bus line connection unit(3) which equalizes the local data bus line with an equal potential level before next column operation, being turned on during the transition of the pass transistor gate signal to a logic low after read operation.
Patent KR-20000067068-A (KR)
Inventor: PARK TEA JIN
IPC: G06F1/16
Filed: 1999-04-22
Abstract: PURPOSE: A printer or personal notebook computer that is stabilized on the tripod and its bag are provided to easily move the personal notebook computer without its bag, to carry the worktable that is needed for personal notebook computer operations, to prevent any damages that can be caused by external impacts during operations and any dangers that can be caused during the operation and the movement of the notebook computer or dismantling and assembling the adapters and the mouse, and to easily move and operate the printer in the outdoor. CONSTITUTION: A conclusion nut(2) that can assemble the tripod is installed on the personal notebook computer(1), the printer(37), and the lower center weight area of the bags(5,38). The suspender ring(3) that can hang the suspenders are installed on the backside of the personal notebook computer and the printer. The bags(5,38) stabilizes and assembles the personal notebook computer and the printer with the exclusive adapters(4) to allow movement and operations. The expandable materials bag(46), the printer bag(38), and the personal notebook computer bag(5) are installed in order on the battery charge box(49) equipped handcart(63) to provide power during outdoor movements.
Patent KR-19990088061-A (KR)
IPC: C10G47/16
Filed: 1999-05-06
Abstract: 본 발명은 적어도 하나의 매트릭스, 하나 이상의 수소화-탈수소화 금속(바람직하게는, 주기율표의 ⅥB 족의 원소 및  Ⅷ 족의 원소에서 선택된 것), 하나 이상의 프로모터 원소, 선택적으로 인, 선택적으로 하나 이상의 ⅦA 족(할로겐)의 원소, 선택적으로 하나 이상의 ⅦB 족의 원소 및 하나 이상의 전체적으로 탈알루미늄화 되지 않은 Y 제올라이트를 포함하는 촉매에 관한 것이다. 상기 제올라이트는 격자 파라미터가 2.438 nm이상, 전체 SiO 2 /Al 2 O 3 의 비가 8이하, 프레임워크 SiO 2 /Al 2 O 3 의 비가 21이하이면서 전체 SiO 2 /Al 2 O 3 의 비이상이다. 본 발명은 또한, 7.5 내지 11 MPA의 특히 낮은 압력하에서, 촉매를 사용해서 하이드로크랙킹하는 방법에 관한 것이다.
Patent KR-19990088243-A (KR)
IPC: C08G18/08
Filed: 1999-05-13
Abstract: 1,3-비스(1-메틸-1-이소시아네이토에틸)벤젠 기재의 카르보디이미드는 카르보디이미드의 중량을 기준하여 12 내지 40 중량%의 에틸렌 옥사이드 단위[-CH 2 -CH 2 -O-]를 함유한다.
Patent KR-20000074697-A (KR)
Inventor: HUH GYEONG UK
IPC: B01D46/00
Filed: 1999-05-25
Abstract: PURPOSE: Provided is an electric collection apparatus containing trap electrodes having a coating layer including a photocatalyst, which is suitable for an application of air conditioners. CONSTITUTION: The electric collection apparatus comprises: an ionization part comprising discharging electrodes and discharging correspondence electrodes to charge contaminated matters in contaminated air to positive; a collecting part comprising the electrodes and corresponding electrodes to pass fresh air by trapping the charged, contaminated matters. The electrodes are coated with metal oxides such as copper oxide, palladium as a reaction accelerator, graphite for adsorbing oil, and titanium dioxide (TiO2) as a photocatalyst for decomposing organic matters.
Patent KR-20010002278-A (KR)
Inventor: HAN YEONG SEOK
IPC: H01L29/78
Filed: 1999-06-14
Abstract: PURPOSE: A method for manufacturing a power semiconductor device is provided to reduce on-resistance and to improve a switching characteristic, by forming an n+ type source region surrounding a shallow p+ diffusion region formed on an epitaxial layer between separated gate electrodes while forming an n+ type source region in a p-type diffusion region outside the gate electrodes. CONSTITUTION: After an epitaxial layer(2) of the first conductivity type is grown on a high density silicon substrate(1) of the first conductivity for a drain, a gate oxidation layer(3) and a highly doped polycrystalline silicon layer are sequentially formed on the epitaxial layer. The polycrystalline layer is patterned to have a desired shape. Diffusion regions(5) of the second conductivity are selectively formed on the epitaxial layer outside the polycrystalline silicon layer using the polycrystalline layer of the pattern as a mask. A central portion of the polycrystalline silicon layer is etched to form separated gate electrodes(4) of the polycrystalline material. A source region(6) of the first conductivity type is formed on the epitaxial layer between the gate electrodes using the gate electrodes as a mask while a source region is formed in each diffusion region. A high density thin diffusion region of the second conductivity type is selectively formed, surrounded by the source region in the epitaxial layer between the gate electrodes. An insulating layer for exposing the source region in the diffusion regions is formed in a region except the source region. A metal interconnection(8) is electrically connected to the exposed source region.
Patent KR-19990078590-A (KR)
Title: 진공펌프
Filed: 1999-06-15
Abstract: 본 발명은 진공펌프에 관한 것으로, 몸체(10), 헤드와 콘(20), 로베(30)는 구상화흑연주철(FCD45)을 재료로 원심주조성형한 후 페이퍼연마로 후가공하고, 로터(40)는 스테인레스 주강(SCS13)으로 정밀주조하여 중삭 및 정삭 후가공하며, 샤프트(50)는 크롬몰리브텐강 4종(SCM440)으로 정삭가공 후 크롬도름을 하여서 성형되는 것에 의해, 부품의 가공성이 향상되고 내부식성, 내산성, 내알카리성, 내마모성과 윤활성이 개선되어 펌핑용량이 향상된다. 
     또, 제품의 코스트 및 유지비가 절약되어 경제적인 이익을 줄 수 있는 것이다.
Patent KR-20010002412-A (KR)
Inventor: LIM SEOK JUNG
IPC: C01G53/00
Filed: 1999-06-15
Abstract: PURPOSE: A method for preparing nickel compounds is provided, from the waste nickel compounds which is generated when nickel is removed from the solution obtained by etching shadow mask. CONSTITUTION: The method comprises the steps of removing most of Fe components from the waste nickel compounds; leaching nickel by using acid, and carrying out complexation, hydrolysis and carbonization of nickel to prepare basic nickel carbonate(BNC; 2NiCO3-3Ni(OH2)-4H2O); and dissolving the basic nickel carbonate in acid, and concentrating and crystallizing it to prepare reagent grade of nickel chloride(NiCl2-6H2), nickel nitrate(Ni(NO3)2-6H2O) and nickel sulfate(NiSO4-6H2). And the method comprises the steps of leaching nickel by using acid; removing most of Fe components from the waste nickel compounds by hydrothermal reaction; and concentrating and crystallizing the residue to prepare industrial Ni compounds.
Patent KR-20010003487-A (KR)
Inventor: HYUN SANG MIN
IPC: H04N7/18
Filed: 1999-06-23
Abstract: PURPOSE: A portable terminal for visual communication is provided to operate the respective LCD(Liquid Crystal Display)s for voice and visual communications by providing two LCDs. The terminal can use selectively two ear pieces and two LCDs. CONSTITUTION: A portable terminal for visual communication includes a body(10), a flip(20), a guide device. The guide device is constructed by a guide rail and a guide groove. A slot(110) for receiving a LCD housing(40) is positioned to an upper end of the body(10). A first LCD(LCD1) is positioned to the slot(110) downwardly. A key pad is positioned to the first LCD(LCD1) downwardly. The portable terminal further includes at least one or more hinge devices for connecting the body(10) to the LCD housing(40) and the guide device for closing and opening the flip(20) from the body(10). The body(10) has an angled bottom end(110a), a planar end(110b) and a side wall(110c) positioned between the angled bottom end(110a) and the planar end(110b).
Patent KR-20010008483-A (KR)
Inventor: LEE DONG UK
IPC: H02J9/00
Filed: 1999-07-01
Abstract: PURPOSE: A sine wave obtaining method is provided to enable an inverter voltage change through parameter variation by controlling voltage of an inverter with a digital control signal of a CPU and an obtained sine wave. CONSTITUTION: A CPU(12) detects a phase of a converter to select a frequency value. DC voltage is outputted according to the selected frequency value to be inputted into phase-option D/A converters(14a,14b,14c). The D/A converters(14a,14b,14c) convert the inputted DC voltage into analog quantity of a sine wave via the CPU(12). The sine wave is filtered through a sine wave filter to obtain a complete sine wave. The sine wave is inputted as a reference signal of a comparator, outputted from the inverter, compared with a feedback voltage, and inputted into a PWM controller. AC voltage from the inverter is controlled by the PWM control signal. So, the digital control signal and the obtained sine wave of the CPU(12) can control the voltage of the inverter.