baber/WOPTO huggingface dataset:
Patent KR-20000026086-A (KR)
Title: Glass material stirrer device for manufacturing cathode ray tube
Inventor: KIM DAE YOUNG
IPC: H01J9/38
Filed: 1998-10-17
Abstract: PURPOSE: A glass material stirrer device for manufacturing a CRT agitates a glass material with a relative low rotation speed, removes a different glass, and reduces a torque applied to a rotation shaft of the stirrer member. CONSTITUTION: A glass material agitation device includes a stirrer tub(1), a gob provider, a rear stirrer member(30,40), and a gob providing stirrer(50). In a stirrer device which makes a glass material which is uniform thermally, chemically and physically, removes a different glass, makes a uniform temperature, the stirrer tub(1) stores/agitates the glass material therein. The gob provider includes a bowl having a glass material, is in association with the stirrer tub, is positioned to a lower part of the bow, and forms a bushing for forming a gob. The rear stirrer members have a rotation shaft rotatable connected to an entrance part of the stirrer tub, and 'X'-format blade mounted to a lower part of the rotation shaft. The gob providing stirrer includes a shaft, a main blade, and auxiliary blade. Thereby, the glass material stirrer device removes a different glass, and reduces a torque applied to a rotation shaft of the stirrer member.
Patent KR-20000026978-A (KR)
Title: Generator using inertial force and the acceleration of gravity
Inventor: JEONG JU HO
IPC: H02K53/00
Filed: 1998-10-17
Abstract: PURPOSE: A generator using inertial force and the acceleration of gravity is provided to produce various electricity by kinds and size of a generator in a non-electric power and a non-pollution way, and to utilizes the electricity in isolated areas, vulnerable areas, and unit areas, by using the inertial force and the acceleration of gravity as energy without having outer electric power. CONSTITUTION: A generator Pully is equipped on a side of a cylinder composition capable of performing up/down movements in a standard of right/left axes. When inclining the cylinder composition to one side, an equipment board of the generator rotates 120 degrees according to the circumference of a circle by the acceleration of gravity and inertia, by following the cylinder composition as a guide. When repeating a push-up operation for a location of the axis(90degrees), to compressed air produced by a starting air tank and a part of electricity, the equipment board of the generator and the generator Pully continuously rotate and produce electricity without having an outer energy source.
Patent KR-20000027331-A (KR)
Title: Anode assembly of magnetron
Inventor: BAEK YOUNG GEUN
IPC: H01J23/02
Filed: 1998-10-28
Abstract: PURPOSE: An anode assembly of magnetron is provided to prevent shifting the setting angle of vanes relative to an anode body by welding the vanes to inner circumferential surface of the anode body with the vanes being sustained in the position. CONSTITUTION: An anode assembly of magnetron comprises an anode body(1), plural vanes(2), and a hopper type pole piece output(6), and a pole piece filter(7). The vanes(2) are radially arranged on the inner circumferential surface of the anode body. The pole piece output(6) is coupled to both of the top and bottom of the anode body and has a central hole formed. Further, on the inner circumferential surface of the anode body, a coupling groove is formed for sustaining and inserting the set angle of the vanes.
Patent KR-20000027523-A (KR)
Title: Micro ball grid array package
Inventor: HONG SUNG HAK
IPC: H01L23/48
Filed: 1998-10-28
Abstract: PURPOSE: A micro ball grid array package is provided to enhance the adherence between the polymide tape and the semiconductor chip, and to prevent the semiconductor chip from being defected by securing spare room enough distance between the surface of the semiconductor chip and the surface of the package. CONSTITUTION: A micro ball grid array package comprises a semiconductor chip(30), a firstpolymide film(32), a bonding material(32a, 36a), a copper layer, a copper pattern(34), a second polymide film(36), a polymide tape(40), a solder ball(50), a dam(60), and a resin(70). The semiconductor chip includes the bonding pads at the edge of the upper side. The polymide tape is attached to the upper side of the semiconductor chip with the bonding material which is attached to the bottom side of the first polymide film. The solder ball is individually connected to the copper patterns through the via patterns. The copper pattern is connected to the bonding pad of the semiconductor chip and the connected area is bonded with the resin.
Patent KR-20000032571-A (KR)
Title: Production of one-component type epoxy modified urethane composition
Inventor: JEON CHAN TAIK
IPC: C08G18/58
Filed: 1998-11-16
Abstract: PURPOSE: A process for producing one-component type epoxy modified urethane composition is provided which prepares the compound which has the advantages of a polyurethane resin and an epoxy resin, which is convenient for use and excellent in storage stability. CONSTITUTION: A preparation method for one-component type epoxy modified urethane composition comprises the steps of (1) mixing a silicon antifoaming agent with an epoxy resin(A) having a molecular weight of 1,000 to 10,000 represented by the formula(1), (2) mixing an excess amount of diisocyanate(B) based on the resin(A), silicon oil and a reaction accelerator with the dehydrated mixture and reacting at 65 to 90°C until the concentration of residual NCO becomes 3.5 to 20% by weight based on the total weight of (A) and (B) and (3) stopping the reaction by a reaction terminator and adding a solvent thereto. The composition is used for adhesives as it stands and paints and coating agents by mixing with dispersion stabilizers and pigments.
Patent KR-19990045400-A (KR)
Title: 다이내믹형 반도체 기억 장치
IPC: G11C11/401
Filed: 1998-11-19
Abstract: 멀티레벨 기록 비트 라인의 중앙 부분에 제공된 전송 게이트의 영역에서, 재기록시에 인접 비트 라인에 미치는 노이즈의 영향이 상보형 비트 라인 쌍의 순서를 역전시킴으로써 제거된다.  따라서, 통상적으로 1개의 센스 증폭기가 복수의 비트 라인을 포함하고 있고 이들 비트 라인중 일부가 시분할 방식으로 선택적으로 활성화되는 멀티레벨 다이내믹형 반도체 기억 장치에서, 인접 비트 라인들간의 노이즈의 영향이 소멸될 수 있다.
Patent KR-20000033168-A (KR)
Title: Method of preparing vinyl chloride resin
Inventor: KIM KYUNG HYUN
IPC: C08F2/44
Filed: 1998-11-20
Abstract: PURPOSE: A preparation method of a vinyl chloride resin is provided which gives the subjected compound excellent in formability and impact strength. CONSTITUTION: A method for preparing a vinyl chloride resin comprises the steps of forming a first polymer by mixing a vinyl chloride monomer with a first initiator and forming a second polymer by adding a vinyl chloride monomer and a second initiator to the first polymer, wherein an organic siloxane polymer represented by the formula 1: -(R1R2SiO)n- is added to the first and second polymer forming step respectively or all together. In formula 1, R1 is 1-12C hydrocarbon containing a substitute selected from the groups consisting of H, alkyl, haloalkyl, aryl, haloaryl, aralkyl, polyether, fluoride, imino, epoxy, and vinyl, R2 is 1-12C hydrocarbon without an unsaturated bond, n is 10 to 2,000. The resin manufactured by the process is excellent in heat stability and impact strength and generates almost no die swell.
Patent KR-20000034035-A (KR)
Title: Bioaugmentation of oil contaminated soil by microbial composition which can decompose hydrocarbons derived from petroleum
Inventor: GU BON TAK
IPC: B09C1/10
Filed: 1998-11-27
Abstract: PURPOSE: A microbial composition for bioaugmentation of oil contaminated soil is produced by optimum fermentation producing the combinations of hydrocarbon decomposing microorganism isolated from oil contaminated soil. Addition of substrates specifically metabolized by microorganism in the composition increases the viability of microorganisms in the contaminated soil and stabilizes and maximizes bioaugmentation. CONSTITUTION: Three hundred of microorganism isolated from oil contaminated soil are screened based on the degradation and emulsification of oil judged from the growth on the plate or liquid culture containing crude oil or gasoline. For the liquid culture test, minimal medium containing 3% of hydrocarbon is used. Acinetobacter sp. W1, Pseudomonas sp. HB26, and Bacillus sp. L11 are selected and cultivated. The culture medium comprises 17-23g/L of glucose, 2-4g/L of yeast extract, 3-4g/L of sodium phosphate, 0.7-1.0g/L of potassium phosphate, 2-4g/L of ammonium sulfate, and very small amount of magnesium sulfate. After the culture, 0.2-0.4% of NaCl, 0.2-0.4% of citrate, 0.15-0.25% of sodium benzoate, and very small amount of sodium phosphate(I, II) are added to preserve the microorganism composition.
Patent KR-19990045672-A (KR)
Title: 표시 제어 회로
IPC: G09G5/377
Filed: 1998-11-28
Abstract: 라인 버퍼수의 증가에 의한 회로 소자수의 증대를 방지하며, 또한 라인 버퍼의 기록 처리 시간의 단축을 도모한다. 
     표시 제어 회로(2)의 입력 소자에는, 표시 메모리로부터의 화면 데이터(b)가 입력되며, 이 화면 데이터(b)는, 투과 제어·우선 순위 제어 회로(12)의 한쪽 단자에 입력된다.  투과 제어·우선 순위 제어 회로(12)의 다른 쪽 단자에는, 라인 버퍼(13)에 축적되어 있는 화면 데이터(g)가 입력되어, 화면 데이터(b와 g)로 투과·우선 순위 제어가 행하여지며, 그 출력 화면 데이터(f)가 라인 버퍼(13)에 입력된다.  투과·우선 순위 제어가 종료한 시점에서 라인 버퍼(13)에 축적된 데이터는, 모니터의 동기 신호에 따라서 화면 데이터(d)로서 출력된다.
Patent KR-19990014639-A (KR)
Title: 납골묘
IPC: E04H13/00
Filed: 1998-11-28
Abstract: 본 발명은 납골묘를 개시한다. 본 발명은 바닥체(10)의 가장자리에 지지턱(12)이 형성되고, 납골 단지(1)가 안치되는 안치실(22)이 형성되도록 바닥체의 지지턱에 측벽체(20;24,26)가 수직하게 설치된다. 측벽체의 하부 외면에는 측벽체의 외면과 맞닿아 측벽체를 지지하기 위하여 보조석(27,28)이 설치되고, 보조석의 상면에 받침판(36)이 얹여 놓여진다. 그리고, 안치실의 전방을 개폐하는 덮개체(30)와 안치실의 후방을 폐쇄하며 비석(50)을 끼워맞춤하기 위하여 덮개체(30)와 맞닿는 전방지지체(60)와 이 전방지지체(60)와 소정의 간격을 둔 후방지지체(62)가 측벽체(24)의 양측상면에 얹여 놓여 있다. 또한 전방지지체(60)와 후방지지체(62)의 사이에는 전방지지체(60)와 후방지지체(62)의 양측면과 맞닿아 결합되는 대면하는 한쌍의 측방지지체(64)가 받침판(36)의 상면에 얹여 놓여 있다. 따라서, 이상과 같이 본 발명에 따른 납골묘는 조립식으로 구성되어 설치 및 해체가 용이하고, 선대와 후대가 함께 안치되는 가족묘로서의 역할을 담당할 수 있다. 또한, 설치 지역의 미관을 살리면서 공간 활용을 겸한 녹지 공원으로 조성할 수 있다.
Patent KR-20000037808-A (KR)
Title: Sealing apparatus for refrigerant injection hole of projection television
Inventor: BOK GI SO
IPC: H04N5/74
Filed: 1998-12-02
Abstract: PURPOSE: A sealing apparatus for refrigerant injection hole of a projection television is provided to prevent bubbles and to seal the refrigerant injection hole more securely. CONSTITUTION: A sealing apparatus for refrigerant injection hole of a projection television includes an elastic material(20) and a combiner. The refrigerant injection hole(30) is implemented in a coupler(28). The coupler(28) includes the refrigerant. The elastic material(20) includes a penetrating hole in a parallel direction with respect to the axis of refrigerant injection hole. The elastic material is inserted in the refrigerant injection hole(30). The combiner includes a pin-type nose inserted into the penetrating hole. The combiner is coupled to the coupler so as to press the elastic material.
Patent KR-20000038262-A (KR)
Title: Tray of disc driving device
Inventor: SONG IN SANG
IPC: G11B33/14
Filed: 1998-12-04
Abstract: PURPOSE: A tray of a disc driving device is provided to minimize the entire noise of the tray by reducing a noise level within 1KHz-1.7KHz to control a noise degree. CONSTITUTION: A tray is equipped a storing face of disc(4), a rear portion(6), an opening(22) and rib(1). The rib controls an airflow flowed in or out through the opening(22). The rib(1) is formed in a form of closed band in a girth of the opening(22). And the rib(1) is projected in the girth of the opening from a lower and a upper faces of the tray. Therefore, the girth of the opening(22) is formed a sill in a lower and an upper faces of the disc storing face(4) and the rear portion(6) by the rib(1). In a recording mode or a playing mode, an airflow is generated between a surface of the disc and the storing face of the disc when the disc is rotated at an omega, an optional rotating angle speed, by driving a spindle motor. The air flow is flowed in and out by penetrating the opening(22).
Patent KR-20000038388-A (KR)
Title: Apparatus for controlling power source of high voltage discharge lamp
Inventor: KIM JEONG SU
IPC: H05B41/36
Filed: 1998-12-07
Abstract: PURPOSE: An apparatus for controlling a power source of a high voltage discharge lamp is provided to reduce the time which is needed to vary the frequency of a power source to stabilize a high voltage discharge lamp. CONSTITUTION: An output voltage detecting section(22) supplies the output voltage to a multiplier(43) of an impedance calculating section(24), and supplies the output current to an amplifier(41) of an impedance calculating section(24). The amplifier(41) of the impedance calculating section(24) amplifies by using the log function, and the output current of the log function is supplied to a differentiator(42). The differentiator(42) supplies the reverse number of the output current. A microprocessor(25) calculates the difference between the present impedance(Z) and the prior impedance(Z1).
Patent KR-19990024125-A (KR)
Title: 자체 냉각기능을 갖는 캔
IPC: B65D81/18
Filed: 1998-12-08
Abstract: 본 발명은 캔용기내에 담겨진 내용물을 별도의 냉각장치를 통하여 냉각시키지 않고서도 그 자체에 내장된 냉매가 내용물을 효율적으로 냉각시켜 식음할 수 있도록 함과 아울러, 그 구성을 단순화 하여 부품의 수를 감소시키고 제조원가를 절감시킬 수 있도록 하며 생산성이 향상될 수 있도록 한 자체 냉각기능을 갖는 캔에 관한 것으로, 이는 금속재의 캔용기내에 냉매실린더(18)를 장착시켜 캔음료의 식음시 상기 냉매실린더(18)내에 주입되어진 냉매를 외부로 배출시켜 캔용기의 본체(12)내에 담겨진 내용물을 자체적으로 냉각시켜 식음할 수 있도록 하는 자체 냉각기능을 갖는 캔에 있어서, 상기 캔(10)의 본체(12)하단에는 상향으로 만곡되어진 로워엔드(16)를 형성하여 상기 로워엔드(16)의 중앙에 상부가 U자형태로 구성되어진 실린더고정구(26)를 캔용기의 내측으로 부터 외측으로 결합시키고, 상기 실린더고정구(26)의 상부 양측으로 상향절곡된 절곡부에는 내부가 중공부로 이루어진 연결관(24)을 매개로 냉매실린더(18)가 일체로 연결되도록 하는 한편, 상기 실린더고정구(26)의 하단은 수나사부(30)로 구성되면서 그 둘레면으로는 소정의 배치간격을 두고 냉매배출공(34)이 각각 형성되고 이 냉매배출공(34)의 개폐는 누름편(44)에 의해 폐쇄부재(36)가 실린더고정구(26)의 수직관통공(38)을 따라 상승하면서 냉매통로(28)를 개방시켜 냉매를 외부로 배출시킬 수 있도록 한 것을 특징으로 한다.
Patent KR-20000039323-A (KR)
Title: Oil supply apparatus having combined structure for airtight type compressor
Inventor: SEO MU HEUNG
IPC: F04B39/02
Filed: 1998-12-12
Abstract: PURPOSE: An oil supply apparatus having a combined structure for an airtight type compressor is provided to easily and simply perform a combining operation of an oil supply apparatus by inserting fixedly a piece in an inserting space, thereby increasing the assembling productivity and improving the safety of the assembling operation. CONSTITUTION: An oil supply apparatus having a combined structure for an airtight type compressor includes an airtight container filled with the oil in the bottom, an electric machine part mounted in the inside of the airtight container for generating a driving power to a stator and a rotor, a compressing machine part for compressing a refrigerant gas by receiving the driving power of the electric machine part, and a crank shaft(6) inserted by pressing into the rotor for transmitting the driving power of the electric machine part, and a piece(13) fixed in the inserting space of a predetermined size formed in the lower part of the crank shaft(6) and fixedly combined in the fixed groove formed in the periphery of the inserting space, having a combined protrusion(13a) opposite to the fixed groove.
Patent KR-20000039429-A (KR)
Title: Method of separating/re-collecting aluminium from waste steel can for drink
Inventor: KWAK SA HO
IPC: C22B7/00
Filed: 1998-12-11
Abstract: PURPOSE: A method is provided to separating/re-collecting aluminium alloy from waste steel cans without melting the aluminium alloy completely. CONSTITUTION: Waste steel cans are re-collected and cut at a proper size or separated to be introduced into a heating furnace easily. The cut two-piece or three-piece steel cans are provided to the heating furnace keeping 400-630°C. After that, aluminium covers and taps are molten and separated from the steel cans by keeping the steel cans in the heating furnace for about 25-35 minutes. A vibrator gives vibration or impact to the steel cans to help the molten aluminium covers and taps to be separated from the steel cans.
Patent KR-20000041459-A (KR)
Title: Image sensor and fabrication method thereof
Inventor: PARK SANG HUN
IPC: H01L27/13
Filed: 1998-12-22
Abstract: PURPOSE: An image sensor and fabrication method thereof are provided to improve photo sensitivity. CONSTITUTION: To fabricate an image sensor, light sensing devices(202), an insulation layer(203), and a light shield layer(204) are successively formed in a substrate. Next, a buffer insulation layer(206) is optionally formed on the substrate. Then, a wedge-shaped hole(207) is formed by a selective etching of the insulation layers(203,206). In addition, a spacer-type reflection layer(208) is formed on sidewalls of the hole(207). After another insulation layer(209) is deposited and planarized on the substrate, color filters(210) are arranged on the insulation layer(209). In particular, since the hole(207) has a wedge shape, a light-condensing efficiency is improved and therefore a photo sensitivity is enhanced.
Patent KR-20000042350-A (KR)
Title: Exhaust grill unit cover of window type air conditioner
Inventor: WHANG YONG HUI
IPC: F24F13/00
Filed: 1998-12-24
Abstract: PURPOSE: An exhaust grill unit cover of a window type air conditioner is provided to prevent foreign matters from flowing in the air conditioner by blocking the exhaust grill unit when the air conditioner is not operated. CONSTITUTION: While an air conditioner(200) is operated, a plate(242) is fitted in a first slot(220), and a bent part(244) is fitted to an upper part of a second slot(230). A cover(240) is pushed in so that the cover is stored in the air conditioner while a handle(246) is only protruded the outside of a front. Herein, since the cover is deeply inserted in the air conditioner, it is desirable to guide the cover by installing the guide on an upper face of a scroll or an upper end of the air conditioner. The handle functions to prevent the cover from falling down in the air conditioner by interrupting the first slot.
Patent KR-20000042425-A (KR)
Title: Inverter chain circuit for low voltage
Inventor: CHO YONG CHEOL
IPC: G11C11/40
Filed: 1998-12-24
Abstract: PURPOSE: An inverter chain circuit for low voltage is provided to reduce power dissipation by reducing the subsidiary threshold current and by improving the delay of movement. CONSTITUTION: An NMOS transistor(N1) is turned on by the input signal of high level for transferring a signal of low level to gate/substrate of a PMOS transistor(P2). And, the PMOS transistor is turned on for transferring a signal of high level to gate/substrate of an NMOS transistor(N3). The NMOS transistor is turned on for transferring a signal of low level to gate/substrate of a PMOS transistor(P4). The PMOS transistor is turned on for outputting a signal of high level as an output signal. Herein, the gates and the substrates of the turned on transistors are connected for reducing threshold voltage by a body effect. Therefore, a signal transfer characteristic and a current driving capacity are improved.
Patent KR-20000042827-A (KR)
Title: Gene involved in incompatibility interactions of plant and pathogen
Inventor: OH BYUNG JUN
IPC: C07K14/415
Filed: 1998-12-28
Abstract: PURPOSE: cDNA clone is isolated by the incompatibility interaction of Capsicum annuum and pathogen. cDNA can express ICC13(incompatible Capsicum annuum -Colletotrichum gloeosporioides interactions) protein involved in the protection of plant from pathogen. CONSTITUTION: cDNA library screening and m RNA differential display method are applied to isolate icc13 gene based on incompatibility interaction of Capsicum annuum and Colletotrichum gloeosporioides. The isolated clone, 1217 bp long, includes 21 bp of 5' untranslated region and 212 bp of 3' untranslated region including polyA tail. One open reading frame, having 328 amino acids, is found. The estimated molecular weight of protein is 36.4 kDa. ICC13 protein has potential catalytic triads, -His-Gly-Gly-Gly-Phe- (-HGGGF-) andmotif found in esterase and lipase of bacteria and mammalian, and -Gly-Ser-Ser-Cyc-Gly- (-GSSCG-) motif found in serine hydrolase. These sequence motifs suggested that ICC13 protein belongs to lipase and esterase family. RNA blotting experiment reveals that icc13 gene is induced by incompatibility interaction of plant and pathogen. icc13 gene is involved in the protection mechanism of plant to pathogen or damage and ripening of seed.
Patent KR-20000043165-A (KR)
Title: Decision device of an equalizer for digital television
Inventor: PARK HWAG DONG
IPC: H04N7/12
Filed: 1998-12-28
Abstract: PURPOSE: A decision device of an equalizer for a digital television is provided to simplify a decision device and reduce an equalizer area by quantizing symbol data to plural levels and multiplexing the quantized data in different levels. CONSTITUTION: A slicer(100) slices inputted symbol data to plural predetermined levels and outputs the plural quantized symbol data. A multiplexor(200) multiplexes the quantized symbol data in response to a control signal. Constants are predetermined by repeated experiments. A multiplier(300) multiplies the quantized symbol data outputted from the slicer(100) by the predetermined constants to output a multiplication signal. An output unit(400) multiplexes the multiplication signal and the quantized symbol data outputted from the slicer(100).
Patent KR-20000043881-A (KR)
Title: Forming method of charge storage electrode of semiconductor device
Inventor: YANG IN GWON
IPC: H01L27/108
Filed: 1998-12-29
Abstract: PURPOSE: A formation of a charge storage electrode is provided to prevent a undesirable micro bridge fail. CONSTITUTION: A first insulating layer(22) is formed on a silicon substrate(21) and then partly etched to form a contact hole. Next, a conductive layer(23) and a second insulating layer are successively formed thereon. The second insulating layer is then etched and a third insulating layer is formed. Next, the third insulating layer is dry-etched and then a spacer is formed on sidewalls of the second insulating layer. The exposed conductive layer(23) is then dry-etched by using both the second insulating layer and the third insulating spacer as a barrier, and therefore the first insulating layer(22) is almost exposed. At this time, the second insulating layer is somewhat removed. Subsequently, by using the third insulating spacer as a barrier, inner portions of the conductive layer(23) is etched so that a remaining part may have a thickness of 1000 to 2500 angstrom. Therefore, a charge storage electrode of stack cylinder type is obtained, and the third insulating spacer is finally removed by wet-etch.
Patent KR-20000044177-A (KR)
Title: Projection type image display device
Inventor: KIM JIN TAE
IPC: H04N5/74
Filed: 1998-12-30
Abstract: PURPOSE: A projection type image display device is provided to embody an optical system of high efficiency using two optical modulators and enhance the uniformity of illumination to remove shimmering phenomenon. CONSTITUTION: A projection type image display device comprises a light source(102), a color filter(104), a hybrid prism(108) and a projection lens(124). The color filter(104) divides light from the light source(102) into a forth color beam, a fifth color beam and a first color beam. The forth color beam is formed by combining the first color beam and a second color beam. The hybrid prism(108) has first to third surfaces(110,112,114). The first surface(110) generates uniform beam. First and second dichroic filters(116,118) for respectively transmitting the second/third color beams and the first beams are attached to the second surface(112). First and second optical modulators(120,122) are attached to the third surface(114). The color beams passing through the prism(108) are projected to a screen by the projection lens(124).
Patent KR-20000044837-A (KR)
Title: Wheel system for projector excellent in rectilinear travel performance
Inventor: CHOI SEUNG U
IPC: G03B21/00
Filed: 1998-12-30
Abstract: PURPOSE: A wheel device for a projector is provided to move a projector to a desired position on a flat surface. CONSTITUTION: A wheel device(200) is combined with the bottom surface of a projector(100). In controlling an image by projecting beam on a screen, the desired direction is easily moved by pushing the projector. Each wheel has a longish shape and is contacted with a surface not to change the forward direction with light external force such as vibration. Thus, the projector goes straight in a regular direction and then settles by stopping rotating the wheel.