baber/WOPTO huggingface dataset:
Patent KR-20000032379-A (KR)
Title: Cool air supplying device of refrigerator
Inventor: CHOI SEUNG UK
IPC: F25D17/00
Filed: 1998-11-13
Abstract: PURPOSE: A cool air supplying device of refrigerator of side-by-side style is provided to variably supply cool air into the freezer chamber and the cool chamber by a single evaporator and a single cooling fan according to the change of inside temperature. CONSTITUTION: A cool air supplying device of refrigerator includes a freezer chamber and a cool chamber by a central partition wall in a cabinet, passages(410,420) formed at upper and lower parts of the partition wall for supplying and feeding back cool air, temperature sensors(600) respectively provided at a proper position in the freezer chamber and the cool chamber for detecting the inside temperature to output a signal, a microcomputer for comparing the signals input from the temperature sensors to output a predetermined control signals, an evaporator(200) provided at a rear part of the freezer chamber for generating cool air while refrigerant is circulating,, a motor(320) provided at an upper part of the evaporator to rotate back and forth according to the control signal output from the microcomputer, and a cooling fan(310) coupled to a motor shaft(322) of the motor for blowing cool air of the evaporator back and forth.
Patent KR-19990073028-A (KR)
Title: 음식물 찌꺼기 사료용 펠렛 성형기
IPC: A23N17/00
Filed: 1998-12-07
Abstract: 본 발명은 음식물 찌꺼기를 이용한 펠렛형 사료를 성형하는 음식물 찌꺼기 사료용 펠렛 성형기에 관한 것으로, 프레임(1) 하부에는 다수개의 캐스터(2)가 부착되고 프레임(1) 상부에는 본체(3)가 설치되고 본체(3)는 중앙에 호퍼(4)와 연결되는 상하 통로(5)와 통로(5)와 수직하게 횡으로 연결되는 도관(6)을 가지며 도관(6)의 양단부에는 펠렛토출구(7)가 설치되고 펠렛토출구(7)에는 내부에 다수개의 구멍(8)이 형성된 펠렛 가이드(9)가 형성되고 외부에는 히팅시스템(10)이 형성되며 본체(3)의 일측 프레임(1)에는 유압실린더(11)가 설치되고 유압실린더(11)의 로드(12)는 본체(3)의 도관(6) 내부를 관통하며 실린더 로드(12)는 도관(6)의 중앙위치에 피스톤(13)을 가지며 실린더 로드(12)에는 피스톤(13)을 중심으로 일정간격으로 마주보게 구멍 청소용 핀(14)이 다수개 설치된 니들부(15)및(16)가 설치되고 하나의 니들부(16)의 이동통로에는 2개의 리미트 스위치(17)및(18)가 설치되며 펠렛토출구(7)의 하부에는 펠렛 사료를 이송하는 배출부(19)및(20)가 설치되고 프레임(1)의 전방에는 콘트롤박스(21)가 설치되게 구성된다.
Patent KR-19990024123-A (KR)
Title: 임펠러축 지지용 동압 유체 베어링을 구비하는 수도미터
IPC: G01F1/115
Filed: 1998-12-08
Abstract: 본 발명은 임펠러형 습식 수도미터에 있어서, 케이싱의 소정부분에 임펠러축을 안정적으로 지지할 수 있는 장치를 부가하여 설치하는 것이다. 임펠러축의 지지장치는 상부 케이싱에 형성된 통공의 내면에 임펠러축과 반경방향으로 소정의 간격을 두고 동압 유체 베어링을 일체로 형성하여 구성하되, 동압 유체 베어링의 저어널에는 저어널의 내면을 따라 하향으로 선회하도록 나선형의 홈부를 형성한다. 따라서, 임펠러축의 회전시 동압 유체 베어링의 저어널에는 유체의 점성에 의하여 나선형 홈을 따라 케이싱의 상측부로부터 유체가 유입되고, 나선형 홈을 통하여 유입되는 유체는 저어널에서 소정의 압력을 형성하게 되며, 형성된 유압에 의하여 고체간의 직접적인 접촉없이 임펠러축이 안정적으로 지지된다. 이에 의하여 임펠러의 회전에 따른 불안정한 진동이나 유동이 현저히 감소된다. 또한, 저어널에 소정의 유압이 형성될 때 이 유압은 상부 케이싱의 상측부로부터 유입되는 유체에 의하여 형성된다. 이에 따라 상부 케이싱 상측부의 유압이 감소되므로 케이싱의 상부에 위치하는 적산표시부 기어들의 회전저항이 감소되므로 최소유량에 대한 수도미터의 계측성능이 향상되고, 유량에 대한 기차가 감소되어 정확한 계량이 가능해진다.
Patent KR-20000004880-A (KR)
Title: Semiconductor device and method thereof
Inventor: YIIDA SATOSI
IPC: H01L21/8239
Filed: 1998-12-21
Abstract: PURPOSE: A semiconductor device and method thereof are provided to prevent a generation of insulating withstand fault of a gate insulator by using dual gate oxide layers. CONSTITUTION: The semiconductor device has a plurality of gate insulators having different film thickness each other. A first gate electrode(4) and a hard mask layer(5) are formed on a first gate insulator(3) in a memory formation region of a silicon substrate(1). A second gate electrode(10) is formed on a second gate insulator(9) having different film thickness compared to the first gate insulator(3) in a logic formation region. A first and a second sidewall insulator layers(8,14) have a different material compared to the hard mask layer(5).
Patent KR-20000041881-A (KR)
Title: Baby pram mounting cassette and speaker
Inventor: LEE YOUNG JOO
IPC: B62B9/00
Filed: 1998-12-17
Abstract: PURPOSE: A baby pram mounting a cassette and a speaker is provided to make a protector listen to desired music and radio broadcasting at any time by mounting a cassette and a speaker on a baby carriage. CONSTITUTION: A cassette is inserted into a groove on a push stick of a baby carriage and fixed with screws. A protector is able to listen to music or radio broadcasting through several slots on left/right support stands of the baby carriage. A speaker is installed toward a lying or sitting baby in the baby carriage. An electric wire between the cassette and the speaker is connected with a space in the carriage.
Patent KR-19990066876-A (KR)
Title: 저납 ed용의 바탕 화성처리방법
IPC: C23C22/36
Filed: 1998-12-28
Abstract: 납을 함유하지 않거나, 또는 납을 저농도로밖에 함유하지 않는 저납 전착도장(電着塗裝)용의 전처리 방법을 제공하는 것을 과제로 한다. 
     이의 해결수단으로는, 금속표면에 교류 임피던스(impedance)법에 의한 부식저항치가 2,500 Ω㎠ 이상이 되도록 인산아연 피막을 형성하는 것을 특징으로 하는, 전착욕 중의 납 농도가 300 ppm 이하, 바람직하게는 실질적으로 0 인 양이온형 전착도장에 유용한, 바탕 금속의 화성(化成)처리방법, 화성처리액 1 ℓ 중에 아연이온을 0.5 ~ 1.5 g, 인산이온을 5 ~ 30 g, 니켈이온을 0.1 ~ 4 g, 망간이온을 0.6 ~ 3 g, 불소이온을 0.05 g 이상, 구리이온을 5 ~ 20 ppm 및 피막 화성촉진제를 주성분으로 함유하는 화성처리액으로 침지처리하는 바탕 금속의 화성처리방법이 있다.
Patent KR-20000043897-A (KR)
Title: Method for fabricating transistor of semiconductor device
Inventor: LEE KYUNG BOK
IPC: H01L27/08
Filed: 1998-12-29
Abstract: PURPOSE: A method for fabricating a transistor of a semiconductor device is provided which can obtain a desired switching effect in the device by preventing the reduction of a threshold voltage by assuring a sufficient channel region. CONSTITUTION: According to the method, a sufficient channel length is obtained by forming a source/drain region(26) with one process, and by forming a gate electrode(30A) by burying a trench with a conductive layer after forming the trench deeply between the source/drain region. A well region(24) is formed by implanting a low dense impurity ion into a semiconductor substrate(21), and the source/drain region is formed by ion implantation of a high dense impurity selectively on the well region. The trench is formed by etching the semiconductor substrate between the source/drain region. And the conductive layer is formed to bury the trench after forming a gate oxide(29) on the whole top structure including the trench. And, finally, the gate electrode is formed in the trench by blanket etching of the conductive layer and the gate oxide.
Patent KR-20000045972-A (KR)
Title: Pre-damper spring of clutch disc
Inventor: SEONG SEO YONG
IPC: F16D13/64
Filed: 1998-12-31
Abstract: PURPOSE: A pre-damper spring of a clutch disc is provided to absorb the distortion vibration by using a buffing rubber, which buffs in cooperation with a coil spring, so that an abnormal noise among gears is reduced and an early abrasion of gears is prevented. CONSTITUTION: A pre-damper spring of a clutch disc comprises: a gear part (11) to be combined with a gear part (42) of a spline hub (40) and to be formed in the middle of a hub flange (10); two spring seats (52) to be made of plastic materials and to be combined with the both end of a coil spring (51); a buffing rubber (53) to be formed in the inner-middle of two spring seats.
Patent KR-20000047237-A (KR)
Title: Gps(global positioning system) terminal having voice service function
Inventor: SHIN HYE YOUNG
IPC: G01C21/00
Filed: 1998-12-31
Abstract: PURPOSE: A GPS terminal having a voice service function is provided to output a user's current position information received from a GPS satellite by a graphic screen or a voice according to a selection of the user. CONSTITUTION: A GPS terminal having a voice service function includes a position information voice storing part(25) for storing a voice data for a geographical information corresponding to a position information received from a GPS satellite, a voice outputting format data storing part(24) for storing a voice data for a voice phrase in a fixed form to be utilized for guiding the position information received from the GPS satellite by voice, a key input part(26) for selectively assigning a voice output or a screen output for the position information received from the GPS satellite, a control part(29) for controlling the voice output or the screen output of the received position information according to an output mode selected by the key input part, and a voice output part(28) for outputting a voice data combining the voice phrase for guiding the position information with the voice data of geographical information as audible sounds.
Patent KR-19990028987-A (KR)
Title: 인덕터
IPC: G07D5/08
Filed: 1996-07-02
Abstract: 인덕터(12)는 틀(20) 위에 감겨진 코일(21)을 포함한다. 틀(20)은 무게비 79% 이상의 페라이트와 폴리 프로필렌 등의 결합재를 포함하는 합성물질을 사출성형하여 만들어진다. 인덕터는 전자식 코인 식별기 등에서 사용되는 전자기 센서에서 이용될 수 있다.
Patent KR-19990063735-A (KR)
Title: 1,2,4-벤조트리아진 옥사이드 제제
IPC: A61K31/53
Filed: 1996-08-21
Abstract: 시트레이트 완충제중에 1,2,4-벤조트리아진-3-아민 1,4-디옥사이드를 포함하는 암종양 치료용 수성 비경구 제제 및 암종양 치료방법이 개시되어 있다.
Patent KR-19990082319-A (KR)
IPC: C21C5/48
Filed: 1997-01-30
Abstract: PCT No. PCT/EP97/00406 Sec. 371 Date Nov. 16, 1998 Sec. 102(e) Date Nov. 16, 1998 PCT Filed Jan. 30, 1997 PCT Pub. No. WO97/28915 PCT Pub. Date Aug. 14, 1997The invention concerns a gas purging bottom for metallurgical vessels, the gas purging bottom comprising a monolithic refractory ceramic lining having channels formed therein by chemical or physical processes. At their ends associated with an adjacent vessel wall, the channels are designed for direct or indirect fluid connection to a gas supply pipe. At their other ends the channels lead into the corresponding outer layer of the refractory ceramic lining.
Patent KR-20000004931-A (KR)
Title: Light guide employing multilayer optical film
Inventor: WHITEHEAD LORNE A
IPC: G02B6/28
Filed: 1997-02-26
Abstract: PURPOSE: A light guide employing multing multilayer optical film is to attain effective spread light and equal light emitting. CONSTITUTION: A light guide(42) having a non light emitting portion(44) made of multiple layers of first and second substantially non absorptive longitudinally specula light reflector materials. The index of refraction of each layer differs from the indices of refraction of the immediately specula reflectivity. A substantially non absorptive light scattering to the light emitting portion(44) in opposition to the emitting(48)
Patent KR-20000015935-A (KR)
Title: Concentrated antibody preparation
Inventor: RELTON JULIAN MARCUS
IPC: A61K38/00
Filed: 1997-05-22
Abstract: PURPOSE: A use of a concentrated single clone antibody preparation is provided to treat diseases such as an angiitis, a rheumatoid arthritis, and a T-cell medium disease. CONSTITUTION: The present invention relates to a concentrated antibody preparation, pharmaceutical formulations containing such a preparation, its use in human therapy and processes for its preparation. Therefore, the concentrated single clone antibody preparation is useful for treating diseases such as angiitis, rheumatoid arthritis, and T-cell medium disease.
Patent KR-19990067761-A (KR)
Title: 자기 디스크장치
IPC: G11B19/04
Filed: 1999-01-07
Abstract: 원판형상 자기디스크매체에 마련된 기록트랙에 자기헤드를 위치 결정하여 정보를 기록하는 자기 디스크장치에 관한 것으로서, 액세스속도를 희생시키지 않고 기록트랙의 위치어긋남을 작게 할 수 있음과 동시에 라이트실패의 발생확률을 저하시켜 신뢰성을 향상시킬 수 있는 자기 디스크장치를 제공하기 위해, 동심원형상 또는 나선형상으로 배치된 트랙을 구비하는 자기디스크매체, 트랙에 대해 기록 또는 재생을 실행하기 위한 자기헤드,기록시에 자기 헤드의 트랙폭방향의 위치정보를 검출하는 검출수단, 위치정보와 여러개의 임계값을 사용해서 자기헤드의 트랙폭방향의 위치어긋남의 크기를 판정하는 판정수단 및 판정수단에 의한 판정결과에 따라서 그 후의 기록트랙을 제한하는 수단을 갖는 구성으로 하였다. 
     이와 같이 하는 것에 의해, 액세스속도를 희생시키지 않고 기록트랙의 위치어긋남을 작게 할 수 있음과 동시에 라이트실패의 발생확률을 저하시킬 수 있고 또 자기 디스크장치의 신뢰성을 향상시킬 수 있다는 효과가 얻어진다.
Patent KR-20000050813-A (KR)
Inventor: KIM HYEONG JIN
IPC: F16D65/82
Filed: 1999-01-15
Abstract: PURPOSE: A protection structure against heat of a brake drum for a vehicle is provided to effectively improve the protection against heat of a brake drum by appropriately designing a cooling fin and a wing fin. CONSTITUTION: A protection structure against heat of a brake drum for a vehicle comprises: a cooling fin (22) to be protruded as an isosceles triangle type in outer face of an expanded opening part (28) of a brake drum (26); a wing fin (24) to be protruded as a band type in the outer face of a cylinder part (30) of the brake drum ,being extended from the cooling fin.
Patent KR-20000056724-A (KR)
Title: A method for the preservation of oil and recalcitrant chemical degrading microorganisms using chitin
Inventor: KIM SANG JIN
IPC: C12N5/02
Filed: 1999-02-25
Abstract: PURPOSE: A preservation method of oil compound degrading microorganisms using chitin is provided which saves time and cost for preservation process of microorganism. CONSTITUTION: Oil compound degrading microorganism is cultured in the inorganic nutrient salt medium containing oil and diluted with the same medium. The diluted culture broth is applied to chitin powder then microorganism is absorbed into the chitin powder. The amount of culture broth is adjusted under 1.5 times of chitin. This process keeps the number of viable cells maximum in the inoculation step and maintains degradability of microorganism. The microorganism used for decontamination of oil compound includes bacteria and yeast and this method can be used to preserve those microorganism. Acinetobacter sp. US1 (KCTC 8618P), Yarrowia lipolytica CL180 (KCTC 0533BP), Sphingomonas sp. KH3-2 (KCTC 8815P), Acinetobacter sp. K2-2, Pseudomonas sp. K12-5 and Moraxella sp. K12-7 are preserved well using this method.
Patent KR-20000059458-A (KR)
Inventor: LEE HYEON JUN
IPC: B41J2/175
Filed: 1999-03-04
Abstract: PURPOSE: An apparatus and a method for checking an ink cartridge of an ink jet printer are provided to check the kind of ink cartridge and whether the ink cartridge is secured in the printer or not even when an output impedance deviation of a detection port in the ink cartridge is larger than a standard deviation of general ink cartridge. CONSTITUTION: An apparatus for checking an ink cartridge of an ink jet printer includes an ink cartridge(100) for outputting ink cartridge data according to an input control signal, a plurality of pull-up resistances(200) connected to the ink cartridge and having different resistance value for the selection of proper resistance value according to an impedance of a cartridge detection port in the ink cartridge, a switching element(300) for connecting the respective pull-up resistances to a power supply(Vcc), and control part(400) for controlling the switching element to selectively connect any one of the pull-up resistances to the power supply according to a predetermined sequence when initiating the system and substituting the ink, and simultaneously checking the ink cartridge data after outputting a control signal to the ink cartridge, wherein the control part controls the switching element to connect all the plurality of pull-up resistances to the power supply in sequence until the ink cartridge data is checked when the ink cartridge data was not checked.
Patent KR-20000060589-A (KR)
Inventor: KIM CHANG NAM
IPC: H05B33/22
Filed: 1999-03-17
Abstract: PURPOSE: A full-color organic EL display panel and a fabricating method thereof are provided to prevent diaphragm damage which occurs when using a shadow mask by forming subsidiary diaphragms thicker than electric insulating diaphragms. CONSTITUTION: Subsidiary diaphragms(5) are provided perpendicularly to first electrodes between luminous areas, buffer layers are formed in the front side, and electric insulating diaphragms(7) are formed in the areas except the luminous areas. The subsidiary diaphragms(5) perform electric insulation between picture elements as the electric insulating diaphragms(7), and prevent damage of the electric insulating diaphragm(7) due to vibration of the shadow mask. So, the subsidiary diaphragms(5) have thickness which is larger than that of the electric insulating diaphragms(7). Then, red organic luminous layers(8-1) are deposited by using a shadow mask, green organic luminous layers(8-2) are deposited by using another shadow mask, and blue organic luminous layers(8-3) are deposited by using other shadow mask.
Patent KR-19990078445-A (KR)
Title: 다공질 층간절연막을 가지는 반도체장치
IPC: H01L21/316
Filed: 1999-03-31
Abstract: 본 발명은 반도체 장치 제조방법에 관한 것이다. 반도체 장치 제조방법에 있어서, 반도체 기판상에 반도체 회로소자 또는 배선패턴이 형성된다. 그 후, 챔버내 산소가스를 포함하는 혼합가스 하에서, 반도체 회로소자 또는 배선패턴을 포함하는 반도체 기판상에 반도체 물질을 산화시켜 층간절연막으로서의 다공질 반도체 산화막이 형성된다
Patent KR-20000065643-A (KR)
Inventor: KO HYEON UNG
IPC: H01L21/02
Filed: 1999-04-07
Abstract: PURPOSE: A filtering device of a semiconductor device scrubber system is provided to lengthen a life time of a cartridge chamber by filtering efficiently a powder type impurity moved with a process gas. CONSTITUTION: A filtering device of a semiconductor device scrubber system comprises a dust collection portion(53), a filter(54), a cooling tube(48b), and a controller. The dust collection portion collects secondary generated materials within a process gas. The filter is installed at an inner side of an upper portion of the dust collection portion in order to intercept the flow of the process gas. The cooling tube is installed at a side wall of the upper portion of the dust collection portion in order to cool the process gas. The controller controls operations of the above components.
Patent KR-20000065652-A (KR)
Title: Satellite antenna coupled to angle measurement device and mounting method of the same
Inventor: KWON TAE IN
IPC: H01Q3/02
Filed: 1999-04-07
Abstract: PURPOSE: A satellite antenna coupled to angle measurement device and a mounting method of the same are provided to measure the angle of the antenna without using an angle meter, a compass, an electro-meter and be greatly simplified. CONSTITUTION: A satellite antenna coupled to angle measurement device comprises bottom and top supporters(2,4), an angle table(6), a stand(7), a stand support(8), a foresight(11) and a sight(12). The supporters(2,4) are respectively connected to the bottom and top edges(1,3) of the antenna and connected each other. A cross mark(4-1) is formed on the center of the supporter(4). The angle table(6) for verifying the angle of the antenna by the shadow formed through the cross mark(4-1) is attached to a front surface of the antenna. Horizontal scales(9,10) for verifying the horizontal and vertical states of the antenna are mounted to the stand support(8). The foresight(11) and sight(12) are mounted on the center of the antenna to verify obstacles in front of the antenna.
Patent KR-20000065664-A (KR)
Inventor: PARK SAEING HYUN
IPC: A47B87/00
Filed: 1999-04-08
Abstract: PURPOSE: An article deposit case is provided to firmly install a door and a door rack. CONSTITUTION: A closed door(2) is fixed on the vertical face of a rotary unit and the bottom of the door is fixed on the horizontal face of the rotary unit. Even if vertical exterior force is applied on the door, the door is not displaced unless the vertical and horizontal faces are bent. When the door is closed after free rotation in open state, a support unit contacts to the upper face of an extension unit and thrust upwardly. A coil spring is compressed. By complete closure of the door, the coil spring is restored and the support unit is inserted to a support groove. Thereby, the door is supported by the restoring force of the coil spring.
Patent KR-20000075085-A (KR)
Inventor: PARK HO JIN
IPC: G05F3/08
Filed: 1999-05-28
Abstract: PURPOSE: An internal operation voltage generation circuit of a semiconductor memory device is provided which can reduce the current consumption in a power-down mode by controlling the internal operation voltage in power-down to be lower than the internal operation voltage in normal operation. CONSTITUTION: An internal operation voltage generation circuit of a semiconductor memory device comprises: a comparison unit(20) which has a differential amplification structure and compares the size of a reference voltage applied through the first input terminal with the size of a distribution voltage applied through the second input terminal and generates a comparison output voltage corresponding to the compared result; a driving unit(22) which is driven in response to the comparison output voltage and outputs the driven result as an internal operation voltage; a voltage distribution unit(24) which is realized by K(<N) transistors which form the first resistance component by being connected between the internal operation voltage and the distribution voltage, and N-K transistors which form the second resistance component by being connected between the distribution voltage and a ground, and distributes the internal operation voltage and outputs the distributed voltage as a distribution voltage; and a resistance conversion unit(26) which converts to increase or to decrease the first resistance component or the second resistance component in response to a power-down enable signal, and varies the internal operation voltage in response to the converted result. The circuit can reduce the current consumed in the power-down mode by controlling the internal operation voltage in the power-down mode to be lower than that in the normal mode.
Patent KR-20010001188-A (KR)
Inventor: DO GI HYEONG
IPC: H02P27/02
Filed: 1999-06-02
Abstract: PURPOSE: A motor driving circuit is provided to use two frequencies as one kind of a motor by analyzing a frequency of an input power supply and controlling a voltage of the power supply based on the frequency of input power supply. CONSTITUTION: A motor(10) is used for a water supply of a washing machine. A power supply(20) supplies a power to the motor(10). A relay(30) connects the power supply(20) to the motor(10) according to a water supply operation of the washing machine and a frequency of the power supply(20). A frequency analyzer(40) analyzes a frequency of the power outputted from the power supply(20) and judges whether the frequency of the power is 50 Hz or 60 Hz. A microcomputer(50) control an operation of a system according the judging result of the frequency analyzer(40). A voltage drop resistor(60) is connected between the motor(10) and relay(30) and drops and applies a voltage to the motor(10) when the frequency of the power supply(20) is 50 Hz. A voltage regulator regulates a voltage supplied from the power supply(20) according to a control signal of the microcomputer(50).
Patent KR-20000005862-A (KR)
Inventor: ROOF TOMASES
IPC: H01L27/108
Filed: 1999-06-03
Abstract: PURPOSE: A vertical type element formed on side wall of word line for manufacturing semiconductor chip and manufacturing method thereof is provided to conduct between a storage node and a bit line in being activated by a word line. CONSTITUTION: The vertical element formed on side wall of word line for manufacturing semiconductor chip comprises: a substrate(20) forming a trench having a storage node in its interior; a word line(30) adjacent to a portion of the substrate under the surface of the substrate; and a vertical type transistor(12), wherein the word line serves as a gate; the storage node and bit line serve as one of a source and a drain; and the transistor conducts between the storage node and the bit line when activated by the word line.
Patent KR-20010002780-A (KR)
Inventor: KIM OK TAE
IPC: H01J29/48
Filed: 1999-06-17
Abstract: PURPOSE: An electron gun for a cathode ray tube is provided to form the different static lens to respective electron beam when beam is deflected into the peripheral part of the screen without adding voltage, and allow all electron beam to be forward-focused into the horizontal and perpendicular directions in the whole screen. CONSTITUTION: An electron gun for a cathode ray tube consists of a plurality of electrodes, a triode part and free focus lens parts(25,26). In the electron gun for a cathode ray tube, a differential circuit(300) differentiates a dynamic voltage synchronized with the deflection current amount of a deflection york.. A primary lens part includes the first focusing electrode(27-1) applied with a direct current having a described potential, the second focusing electrode(27-2) applied with the wave form of the dynamic voltage differentiated in the differential circuit and the third focusing electrode(27-3) applied with the dynamic voltage.