baber/WOPTO huggingface dataset:
Patent KR-20040051393-A (KR)
Title: Combination structure of dial-swicth for car
Inventor: PARK JU HWAN
IPC: G05G1/10
Filed: 2002-12-12
Abstract: PURPOSE: Structure for connecting a dial switch of a vehicle is provided to improve reliability even at a high temperature by enhancing the connecting force between a shaft member and an elastic member. CONSTITUTION: An elastic part(40) having a gap(42) for inserting a fixing piece(34) is made of a spring. The elastic part includes a fixing ledge(44) protruded toward the inside of the elastic part. A shaft member(50) combined with the elastic part includes a first circumference(52) and a second circumference(54) having a diameter shorter than that of the first circumference. A first stepped portion(60) and a second stepped portion(62) are formed on both ends of the second circumference. The fixing ledge of the elastic part is stopped at the first and second stepped portions.
Patent KR-20040054154-A (KR)
Title: A Method and an Apparatus for Fabricating Micro-channel Plate Using Corrugated Molds
Inventor: KIM PO JIN
IPC: B05D3/00
Filed: 2002-12-18
Abstract: PURPOSE: A method and an apparatus are provided to allow for ease of manufacture of micro-channel plate by depositing a secondary electron emitting material on substrates and stacking the substrates. CONSTITUTION: A method comprises a step of disposing a flat first substrate on a convex-concave mold; a step of heating the first substrate, and permitting both sides of the first substrate to have a convex-concave shape by applying vacuum to the lower surface of the first substrate and pressure to the upper surface of the first substrate; a step of depositing a secondary electron emitting material on the surfaces of a convex-concave first substrate(111a) and a flat second substrate(114); and a step of forming a micro channel(116) by alternately stacking the convex-concave first substrate and the flat second substrate deposited with the secondary electron emitting material.
Patent KR-20030014661-A (KR)
Title: internet Travels information receive the compensation
Inventor: RIM JAE KEAN
Filed: 2002-12-21
Abstract: PURPOSE: A method for supplying, collecting, and compensating travel information is provided to calculate a travel expense, perform a reservation, and purchase an airline ticket by comparing destinations and bureaus on the Internet. CONSTITUTION: A plurality of information necessary for a travel is stored in a database and a contract is concluded with a travel bureau. Information such as a usage, the present reservation condition, weather forecasting information, and the current weather, etc. is inquired and updated by sharing the database and using an on-line, an off-line, and a wire/wireless communication network. A member joining process of a member store or a user is performed, personal information and information of an account and a credit card are received. At this time, important data are coded and stored in the database. A photograph travel book is stored in the database according to individuals. A member compares ones' destinations in travel and travel bureaus therewith, calculates a travel expense, performs a reservation, and purchases an airline ticket. A place adapted to a condition is searched in a site in accordance with a request of a member, and a reservation and a payment are performed in the site for the member using information of a registered member.
Patent KR-20040056555-A (KR)
Title: Method of forming a vertical taper based on diffusion-limited etching
Inventor: BAEK YONG SUN
IPC: G02B6/13
Filed: 2002-12-24
Abstract: PURPOSE: A method for forming a vertical taper using a diffusion phenomenon is provided to enhance a degree of integration of an optical device and simplify conditions of an etching process by using a diffusion-limited etching method to form the vertical taper. CONSTITUTION: A lower peripheral layer(2) of a waveguide, a center layer(3) of the waveguide, an upper peripheral layer(1) of the waveguide, and a selective etching layer(7) are sequentially formed on a substrate. A long ribbon-shaped etching mask(6) is formed on the selective etching layer. The selective etching layer is etched to the inside of the etching mask by using a selective etching solution. A capillary flat plate is formed by the etching process. The upper peripheral layer of the waveguide is partially etched by using the diffusion-limited etching solution.
Patent KR-20040057425-A (KR)
Title: Method for cutting non-metallic material substrate and equipment for cutting non-metallic material using the same
Inventor: LEE BONG U
IPC: G02F1/13
Filed: 2002-12-26
Abstract: PURPOSE: A method and an apparatus for cutting a non-metallic substrate are provided to remove particles generated during a cutting process of the non-metallic substrate, thereby preventing the particles from scattering and attaching again to the non-metallic substrate. CONSTITUTION: A TFT(Thin Film Transistor) substrate member(110) is formed at least one or more positions of the first non-metallic substrate. The TFT substrate member(110) includes a plurality of TFTs and pixel electrodes connected to each TFT. The TFT substrate member(110) is cut, thereby forming a TFT substrate. A color filter substrate member(130) is formed at the second non-metallic substrate and has the number which is the same as that of the TFT substrate members(110). A liquid crystal fence for receiving a liquid crystal is formed at one of the first and second substrates(100). After injecting the liquid crystal, the first and second substrates(100) are assembled with each other, thereby forming an assembly substrate(140). An LCD(Liquid Crystal Display) unit cell(150) is separated from the assembly substrate(140). The cut LCD unit cell(150) is called as an LCD panel(160). A driving module(170), for example, an FPC(Flexible Printed Circuit)(172) or a PCB(Printed Circuit Board)(175), is combined to the LCD panel(160).
Patent KR-20040059024-A (KR)
Title: A method for detecting center temperature of charter
Inventor: CHO JIN SU
IPC: C21B7/24
Filed: 2002-12-27
Abstract: PURPOSE: A method for detecting temperature of central point of hot metal is provided to detect central point temperature of hot metal by moving a hot metal temperature detector to the calculated central point of hot metal after calculating central point of hot metal by detecting vertical and horizontal hot metal temperature distribution charts. CONSTITUTION: The method comprises a step of detecting an X axis directional temperature distribution of hot metal as moving traveling transfer car in the state that tilting angle (θ) of measuring nozzle is fixed; a step of detecting a Y axis directional temperature distribution of hot metal as adjusting the tilting angle (θ) of the measuring nozzle in the state that traveling distance (L1) of the traveling transfer car is fixed; a step of dividing hot metal sections through temperature comparison from the detected X and Y axis temperature distributions, and calculating center of the divided X and Y axis hot metal sections as hot metal central point (P); a step of calculating the traveling distance (L1) of the traveling transfer car and the tilting angle (θ) of the measuring nozzle so that temperature sensor of hot metal temperature detector is positioned at the calculated hot metal central point (P); a step of detecting central point temperature of hot metal using the temperature sensor after moving the traveling transfer car and the measuring nozzle according to the calculated traveling distance (L1) and tilting angle (θ); a step of comparing the detected hot metal central point temperature with a set reference temperature range; and a step of detecting hot metal central point temperature again by changing the calculated traveling distance (L1) and tilting angle (θ) a little at a time if the detected hot metal central point temperature is deviated from the set reference temperature range.
Patent KR-20040060540-A (KR)
Inventor: JANG JEONG OK
IPC: G09G3/36
Filed: 2002-12-30
Abstract: PURPOSE: A driving circuit of a liquid crystal display device is provided to reduce the overall cost since an additional high voltage driving integrated circuit(IC) is not required by performing the high voltage driving with a low voltage driving(IC). CONSTITUTION: A driving circuit of a liquid crystal display device includes a data driving integrated circuit(IC)(51), a charging pump circuit(52), a plurality of capacitors(53) and a plurality of switches(54). The data driving IC(51) generates a low voltage. The charging pump circuit(52) pumps the charges by receiving the external common voltage and to output the pumped charges. The plurality of capacitors(53) is installed on each of the output terminals of the data driving IC(51) for storing the voltage charged at the charging pump circuit(52). And, the plurality of switches(54) is installed each of the output terminals of the data driving IC(51) selectively outputting the voltage outputted from the data driving IC(51)and the output voltage of the capacitors(53) in response to the external polarity control signal and the inverted polarity control signal.
Patent KR-20040062008-A (KR)
Title: Frequency oscillation apparatus for dual mode terminal
Inventor: LEE JAE HWAN
IPC: H04B1/40
Filed: 2002-12-31
Abstract: PURPOSE: A frequency generator of a dual mode terminal is provided to reduce the overall number of parts by providing a reference frequency to two modems by using one reference frequency oscillator. CONSTITUTION: A CDMA block(10) wirelessly communicates with outside through a CDMA frequency band. A W-CDMA block(20) wirelessly communicates with outside through a W-CDMA frequency band. An automatic frequency control switch(41) receives an automatic frequency control signal from the W-CDMA block(20) and selectively outputs it. A reference frequency oscillator(42) generates and outputs a desired RF(Radio Frequency) to RF blocks(12,22) of the CDMA block(10) and the W-CDMA block(20) according to the automatic frequency control signal. A digital signal processor(31) maintains a call available state by controlling the CDMA block(10) and the W-CDMA block(20).
Patent KR-20040062193-A (KR)
Inventor: CHAE GI SEONG
IPC: G02F1/136
Filed: 2002-12-31
Abstract: PURPOSE: A thin film transistor and a method for manufacturing the thin film transistor are provided to simplify a process of fabricating the thin film transistor. CONSTITUTION: A thin film transistor includes a gate electrode(30), a gate insulating layer(31), a semiconductor layer(40), and source and drain electrodes(33). The semiconductor layer is formed of CdSe. The source and drain electrodes are formed of a multi-level metal including ITO(indium tin oxide)(41) and a row-resistance metal(42). A portion of the source and drain electrodes, which comes into contact with the semiconductor layer, is made of ITO. The row-resistance metal includes copper, molybdenum and chrome.
Patent KR-20020022782-A (KR)
IPC: C07F9/14
Filed: 1999-11-08
Abstract: 옥시삼할로겐화인과 비스페놀 A 유도체를 특정 비율로 반응시켜 포스포로할리데이트를 제조하는 제1공정; 미반응의 옥시삼할로겐화인을 제거하는 제2공정; 상기 제2공정에서 얻은 반응 산물과 모노페놀계 화합물을 120℃ 이하에서 반응시키는 제3공정; 및 상기 포스포로할리데이트와 모노페놀계 화합물을 120℃ 이상에서 반응시키는 제4공정을 포함하는 방법에 의해서, 축합형 인산 에스테르가 수지용 첨가제로 사용될 때 내열성의 저하와 성형시 금형 오염의 원인이 되는 이소프로페닐 페닐 디페닐 포스페이트의 함유량이 매우 낮은 축합형 인산 에스테르가 제공된다.
Patent KR-20020037337-A (KR)
IPC: H01L21/8242
Filed: 2000-06-16
Abstract: 본 발명에 따르면, 질화 규소 결정층을 형성하기 위한 방법은 실리콘 결정 기판에 노출된 표면을 제공하는 단계, 수로 프리베이크를 사용하여 상기 노출된 표면을 미리 세척하는 단계 및 질화 규소 결정층을 형성하기 위하여 상기 노출된 표면을 질소에 노출시키는 단계를 포함한다.  또한, 본 발명에 따른 트렌치 커패시터는 자연 산화막이 실질적으로 없는 표면을 갖는 깊은 트렌치를 포함하는 실리콘 결정 기판을 포함한다.  질화 규소 결정층을 포함하는 유전체 스택은 상기 트렌치의 측벽상에 형성된다.  상기 유전체 스택은 상기 트렌치 커패시터의 전극 사이에 노드 유전체를 형성한다.
Patent KR-20020060731-A (KR)
IPC: C03B23/047
Filed: 2000-11-10
Abstract: 본 발명에 의한 광학 렌즈의 제조방법은, 제 1 투광성 재료에 의해 기둥 형상으로 형성되는 동시에, 곡면 형상으로 형성된 제 1 광학 작용부(11)를 측면에 갖는 제 1 광학 부재용 모재(40)를 제작하는 제 1 광학 부재용 모재 제작 공정과, 제 1 광학 부재용 모재 제작 공정에 의해 제작된 제 1 광학 부재용 모재를 원하는 외경으로 될 때까지 드로잉 처리하는 제 1차 드로잉 공정과, 제 1차 드로잉 공정에 의해 드로잉 처리된 제 1 광학 부재용 모재(40)를 슬라이스 가공하여, 기둥 형상을 갖는 제 1 광학 부재(2)를 제작하는 제 1 광학 부재 제작 공정을 구비한 것을 특징으로 한다. 이러한 광학 렌즈의 제조방법에 의하면, 제 1차 드로잉 전의 모재의 단계에서, 광학 렌즈의 형상, 특히 제 1 광학 작용부(11)의 형상을 결정할 수 있기 때문에, 충분히 큰 사이즈로 모재의 가공을 행할 수 있고, 간단하고 정확하게 이것들의 작업을 행하는 것이 가능해진다.
Patent KR-20020073341-A (KR)
IPC: A61K39/00
Filed: 2000-11-29
Abstract: 본 발명은 알츠하이머 질병 및 기타 아밀로이드 관련 질병의 예방 및/또는 치료용의 입체화학계 "비-자기" 항원 백신에 관한 것이다.  본 발명에서는 알츠하이머 질병 및 기타 아밀로이드 관련 질병의 예방 및 치료용 백신으로서, 천연 발생적 펩티드, 단백질 또는 면역원을 이용하는 것과 관련된 단점을 극복한 백신을 제공한다.
Patent KR-20020081678-A (KR)
Title: 확산 스펙트럼 시스템용 수신기
IPC: H04B1/707
Filed: 2000-12-08
Abstract: 본 발명은, 확산 스펙트럼 시스템의 수신기의 동작을 위한 방법으로서, 상기 수신기에서 수신되는 신호는 수신되는 시간 및 주파수를 가지며, 송신되는 시간 및 주파수를 가지고 소정의 변조 스킴에 따라 송신기로부터 송신되고, 상기 수신되는 신호 및 상기 송신되는 신호 간에 시간 오프셋 및 주파수 오프셋이 존재하며, 상기 수신기는 상기 소정의 변조 스킴에 따라 미리 정의된 상관면을 포함하는 방법에 있어서, 상기 수신기에서 예기되는 신호를 생성하는 단계로서, 상기 예기되는 신호는 상기 송신기 주파수로부터 편이되는(shifted) 주파수 파라미터 및 상기 송신기 시간으로부터 편이되는 시간 파라미터를 포함하는 시간 및 주파수의 함수인 단계; 상기 수신되는 신호의 수신되는 시간 및 주파수를 그들간에 각각의 상관 정도를 제공하기 위하여 상기 예기되는 신호의 시간 및 주파수 편이 파라미터들과 상관시키는 단계; 상기 상관면을 사용하여, 상기 시간 오프셋과 상기 시간 편이를 합한 것만큼 시간적으로 이동된 그리고 상기 주파수 오프셋과 상기 주파수 편이를 합한 것만큼 주파수적으로 이동된 지점에서 상기 상관의 값을 나타내는 계산에 관한 표현을 유도하는 단계; 및 상기 시간 오프셋 및 상기 주파수 오프셋을 결정하기 위하여 상기 상관 정도를 상기 계산에 관한 표현과 비교하는 단계를 포함하는 방법을 개시한다.
Patent KR-20020073188-A (KR)
Title: Akylation process
IPC: C07C2/72
Filed: 2001-01-29
Abstract: A side-chain of a substituted aromatic compound is alkylated by reacting the aromatic compound with an alkylating agent in the presence of a catalyst. The catalyst comprises a restructured smectite clay to which basic ions are incorporated by ion-exchange. The restructuring of the smectite clay is carried out by acid-treating the clay prior to ion-exchange.
Patent KR-20030040195-A (KR)
IPC: G16H20/70
Filed: 2001-01-23
Abstract: 약물과 연관된 인지 효과를 정량화하는 발명.
Patent KR-20020087960-A (KR)
Title: 부재의 수수 장치, 부재의 수수 장치의 제어 방법,집적회로 검사 방법, 집적회로 핸들러 및 집적회로 검사장치
IPC: G01R31/28
Filed: 2002-01-31
Abstract: 구동축을 2축에 의해 구성하고, 그 각각의 구동축의 일단에 구동축을 회전 구동하는 구동계(4)를 접속하고, 각각의 타단측에 IC를 유지하는 유지부(5a, 6a)를 구비한 유지 반송 기구(5, 6)를 접속하고, 각 유지 반송 기구(5, 6)를 독립적으로 동작 가능하게 구성한 것이다.
Patent KR-20030022142-A (KR)
Title: Polishing pad with built-in optical sensor
IPC: B24B49/00
Filed: 2000-07-03
Abstract: An wafer polishing pad assembly for use in CMP includes an optical sensor for sensing reflectivity of the wafer during polishing, and produces a corresponding signal, and transmits the signal from the rotating pad to a stationary portion of the assembly. The signal is transmitting off the pad through non-contact couplings such inductive coupling or optical couplings after being converted into signal formats enabling non-contact transmission.
Patent KR-20030037232-A (KR)
IPC: A23L7/104
Filed: 2001-06-19
Abstract: 본 발명은 전분 및 단백질의 추출가능성 및 회수를 증강시키기 위하여 티오레독신 및/또는 티오레독신 리덕타제를 사용하는, 옥수수 및 대두 같은 곡물의 신규한 가공 방법을 제공한다.  본 발명은 추가로 열안정성 티오레독신 및/또는 티오레독신 리덕타제를 발현하는 신규한 유전자이식 식물을 제공한다.
Patent KR-20040064748-A (KR)
Title: Electronic valve
Inventor: PARK GWANG HUI
IPC: F16K31/06
Filed: 2003-01-10
Abstract: PURPOSE: An electronic valve is provided to improve the reliability of the valve and lengthen the life span of the valve by using permanent magnets. CONSTITUTION: An electronic valve is composed of an inflow port(10) having an inlet(15) and an outlet(15'), a spring(25) for supporting a shaft(30) integrated with a diaphragm(12) upward, an isolation member(40) installed at the top of the shaft and attracting a first iron member(55), first permanent magnets(50) installed at the top of the first iron member, a fixed plunger(65) installed at the top of the first iron member and magnetized by the first permanent magnet, a coil(20) installed at the top of the fixed plunger and generating electromagnetic force, a movable plunger(60) installed in the coil and moving downward by the electromagnetic force to keep the valve open, second permanent magnets(70) for magnetizing a second iron member(75) integrated with the top of the movable plunger, and a hand-operated unit(80). The hand-operated unit is disposed at the top of the movable plunger, and moves into the lower part of the movable plunger by the spring.
Patent KR-20040064755-A (KR)
Inventor: CHOI IN SU
IPC: H01J9/26
Filed: 2003-01-10
Abstract: PURPOSE: An apparatus and a method for encapsulating a display panel are provided to encapsulate a large amount of the panels within a short time by guiding continuously the panels to a heating unit. CONSTITUTION: An apparatus for encapsulating a display panel comprises a main body(110), a conveyer unit(120), and a heating unit(130). The inside of the main body is vacuum state and an inlet and an outlet are formed at one side of the main body. The conveyer unit is formed on the inside of the main body and transfers vertically the panel supplied through the inlet and exhausts the panel to the outlet. The heating unit is formed on the space to which the panel is moved by the conveyer unit and heats the panel for fusing a frit in order to encapsulate the panel.
Patent KR-20040064930-A (KR)
Inventor: BANG SEOK WON
IPC: G05D1/02
Filed: 2003-01-11
Abstract: PURPOSE: A mobile robot and an autonomous system and a method thereof according to the mobile robot are provided to improve the accuracy of movement by switching light sources of a land mark installed on a working space to control them and find out a position of the mobile robot. CONSTITUTION: A communication module(502) transmits a light source control signal for selectively switching and controlling a light source of a land mark installed on a working space. An image processing module(503) detects the switching and controlling of the light source according to the light source control signal from an external image signal to read a camera coordinates value of the light source. A position calculating module(504) calculates the position coordinates of a mobile robot(500). A motion controlling module(505) has the calculated position coordinates of the mobile robot corresponding to the space coordinates of a stored working space to set a moving path to a destination and to drive the mobile robot. A main controlling module(501) controls operation between the modules and the whole operation of the mobile robot.
Patent KR-20030021188-A (KR)
Title: Device and method for sterilizing and cleaning
Inventor: SEO YEONG SEOK
IPC: A61L2/025
Filed: 2003-01-14
Abstract: PURPOSE: Provided are a device and a method for sterilizing and cleaning at the same time by the ultrasonic wave. The device is portable and easily assembled to widen its application and increase its efficiency. CONSTITUTION: The device for achieving sterilization and cleaning at the same time is characterized by comprising the parts of: an aquatic plant fitted on the surface of the plate of a ultrasonic wave vibrator; and an aquatic plant shaped part fitted under the plate symmetrically to use it reversely. It sterilizes an object to be sterilized by vibration of the ultrasonic wave, and simultaneously clean its parts in the aquatic plant.
Patent KR-20030081007-A (KR)
Inventor: KANG GYU YEONG
IPC: G01S19/13
Filed: 2003-01-15
Abstract: PURPOSE: A GPS receiver interface apparatus of a flash memory card reader is provided to supply power to a GPS receiver through the interface apparatus. CONSTITUTION: According to the apparatus interfacing a flash memory card reader(20) connected to a computer(5) with a GPS receiver(25), a power supply part(60a) receives a power source from a USB port(10) installed in the above flash memory card reader. An interface part(60) receives data transmitted from a micom(40) in the flash memory card reader as a RS-232 signal. And a connector(45) connects the power source supplied from the power supply part and the data received in the interface part to the GPS receiver. The communication port is a USB communication port or an IEEE-1394 communication port.
Patent KR-20040068667-A (KR)
Inventor: JANG YEONG SU
IPC: G11B7/004
Filed: 2003-01-27
Abstract: PURPOSE: A device for generating a recording pulse is provided to convert NRZI(Non Return-to-Zero Inverted) signals into 6 window signals, and to delay the 6 window signals according to time delay data, then to combine the signals to generate a recording pulse, thereby improving recording properties. CONSTITUTION: An NRZI pattern analyzer(10) outputs an address value and a delayed NRZI signal from an NRZI signal. A window signal generator(11) generates 6 signals corresponding to a length of a mark from the delayed NRZI signal. A write strategy RAM(13) stores plural address values and time delay data values corresponding to the address values. A phase controller(14) outputs one of plural voltages for generating plural delay clock signals. A pulse generator(12) delays the plural signals outputted from the window signal generator(11), respectively, according to the time delay data, combines the delayed signals, and generates a recording pulse and an erase pulse.
Patent KR-20040071924-A (KR)
Inventor: LEE MYEONG EUN
IPC: H04B1/38
Filed: 2003-02-07
Abstract: PURPOSE: A mobile terminal having an internal battery pack is provided to dispose more key buttons on a front surface keypad by arranging directional keys at a rear surface of a mobile terminal. CONSTITUTION: A battery pack insertion hole(13) is formed long at one side of a terminal body(100) between a rear surface and a front surface(11) of the terminal body(100), and a battery pack(14) is coupled into the battery pack insertion hole(13). A hooking protrusion(16) is formed at both sides of a cover plate(15) formed at one end portion of the battery pack(14), so that when it is inserted into the battery pack(14), it cannot easily released from the battery pack insert hole(13). More buttons(24) can be disposed at the front surface(11) of the terminal and the size of the buttons can be increased, so that a user can easily input information.
Patent KR-20040075202-A (KR)
Inventor: HONG SEUNG DAE
IPC: G06K17/00
Filed: 2003-02-20
Abstract: PURPOSE: A loop antenna fixed to an outer case and a credit card reader equipped with the same are provided to use a contact and a contactless card by equipping with the loop antenna and an RF(Radio Frequency) recognition module, and easily install a structure of a present contact card reader when the RF recognition module is installed. CONSTITUTION: An upper cover(140) is equipped with a display window(120), a card inserting slot(130), and a dial(100) of the credit card reader(100). A lower base(145) forms the outer case of the credit card reader by being combined with the upper cover as one body. A signal processing PCB(Printed Circuit Board)(168) installed to the lower base includes an RF processor processing an RF signal and outputting a digital signal, and a signal processor processing the digital signal. The loop antenna(162) combined with the RF processor has a bent shape, in order to be placed to an inner side of the upper cover, form a loop along a corner of the upper cover, and place the loop to an upper part and a side of the upper cover in case that the upper cover is combined with the lower base.
Patent KR-20040030187-A (KR)
Inventor: KISHIOKA HIROAKI
IPC: C09J7/22
Filed: 2003-02-21
Abstract: PURPOSE: A pressure-sensitive double-sided adhesive tape, a method for fixing a touch panel to a display device by using the adhesive tape and a fixing structure of a touch panel to a display device containing the adhesive tape are provided, to improve re-adhesion without the deterioration of transparency and to inhibit the reduction of transmittance from a display device and to prevent the change of color. CONSTITUTION: The pressure-sensitive double-sided adhesive tape(1) comprises a transparent sheet(2); a first transparent pressure-sensitive adhesive layer formed on the one face of the transparent substrate; and a second transparent pressure-sensitive adhesive layer formed on the other face of the transparent substrate. The first face(3) of the adhesive tape is adhered substantially to the entire face of a touch panel and the second face(4) is adhered substantially to the entire display face of a display device.