세그먼트 코드 LCD LCD 드라이버 방법 First of all, do not think that with the microcontroller to drive the segment code screen is DC-driven, in fact, segment code screen is AC drive, what is AC? Rectangular wave, sine wave and so on. Everyone may often use the driver chip to play, such as the HT1621, but some segment screen IO ports are less, or if the IO 포트 is 충분, u can also save the write controller driver. the interface with the MCU is convenient, while the latter has a small drive current, low power consumption, long life, beautiful shape, clear display, large viewing angle, flexible driving mode, and wide application. 그러나, the LCD on the control is more 복잡한 because the relative DC value between the LCD 전극 must be % 7b{2}}. 그렇지 않으면 , the LCD will be oxidized 쉽게. 그러므로, the LCD cannot be controlled by the level signal simply. 대신, a square wave wave sequence with a certain waveform is used. control.
그만큼 LCD 디스플레이 있다 둘 모드 의 정적 및 시간 나눗셈. 그 전자 is 단순, 그러나 필요 더 lines; the latter is 복잡한, but 필요 적은 라인. 이들 둘 모드 are 결정된 전극 리드 선택 방법. 그 다음 용도 the 액체 크리스탈 디스플레이 의 전자 시계 as an 예. 그 높은 시간 의 the 시간 is 또한 꺼짐 또는 켜짐. 언제 the 높은 숫자 의 분 쇼 the 디지털 숫자 1 to 5, the top and bottom are also off or on at the same time. the two dot points are also on or off at the same time. The driving method is divided driving with a bias ratio of 1/2, and there are 11 segment electrodes and two common electrodes. 그러나, there is a precondition for IO analog-driven liquid crystal display, that is, IO must be 3-상태. 왜?
LCD 세그먼트 LCD 화면
여기's 무엇 우리're 말하기 함께:
그만큼 첫번째 단계, 더 중요한 매개변수 의 더 세그먼트 코드 LCD: 작동 전압, 듀티 사이클, 바이어스 비율. 이들 셋 매개변수 아르 매우 중요 및 반드시 되는 충족.
그만큼 초 step, 드라이빙 방법: 일치 에 the 드라이빙 원리 의 the LCD, 만 the AC 전압 can be added to the LCD pixel. the contrast of the LCD display is determined by 빼기 전압 값 on the SEG 핀 에서 전압 값 에 COM 핀. 언제 이 전압 차이 채도 전압 크 다음 보다 LCD 캔 열기 더 픽셀, 및 그것 캔 턴 끄기 픽셀 언제 LCD 임계값 전압 이다 낮다. LCD 유형 MCU 있다 자동 생성 LCD 드라이브 신호 에서 내장 LCD 드라이버 회로. 그러므로, as long as the I/O port can simulate and output the drive signal. , you can complete the LCD driver.
세그먼트 코드 LCD 스크린 있다 둘 메인 핀, COM, SEG, 유사 to the 디지털 튜브, 그러나 the 압력 차이 must be 교대, such as the the 처음 순간 is a positive 3V, then the second moment must be reversed 3V It is important to note that if the segment code LCD panel is powered by DC, the screen will be wasted for a long time, so be careful. Let's consider how to simulate the COM port waveform. Take 1/4D, 1/2B as an example:
At the same time, we must pay attention to, when the COM output is high, if the screen is on, SEG will output low, then when the COM output is low, SEG will output high, ensure that the pressure difference between COM and SEG is greater than 1/2B operating voltage It can be displayed
when the SEG level is reversed with the COM level, driving the segment LCD is 기본 성공.
섹션 코드 LCD 기본 지식
The 액체 결정 디스플레이 is a 패시브 디스플레이, it 할 수 없음 방출 빛, 캔 only 사용 주변 빛. 그것 쇼 만 a 작은 양 의 에너지 위해 패턴 또는 캐릭터. 때문에 의 낮은 전력 소비 및 소형화, LCD 있다 되다 a 더 좋아지는 디스플레이 방법.
The liquid crystal material used in the the liquid crystal display is an organic material having both liquid and solid properties. Its rod-like structure is generally arranged in parallel within the liquid crystal cell, but it can change its alignment direction under the action of an electric field.
For a positive TN-LCD, when no voltage is 적용 to the 전극, the LCD is in the "OFF" state, and the 빛 에너지 is transmitted through the LCD in the white state; when the voltage is applied to the 전극, the LCD is in the "ON" state, the long axis direction of the 액체 crystal molecules. 배열된 in the 방향 의 the 전기 field, the 빛 할 수 없음 통과 통과 LCD 및 나타남 검은색. 선택적으로 적용 a 전압 가로 the 전극, 다른 패턴 가능 있음 표시.
for the STN-LCD, the twist angle of the 액체 crystal is larger, so the contrast is better and the viewing angle is wider. STN-LCD is based on 복굴절 이론, its basic color is generally yellow-green, font blue, yellow green model. when using a purple polarizer, the base color turns gray to become a gray mold. when using a polarizing film with a compensation film, the base color will 거의 하얗게 된다. 에서 이 시간, 더 STN 된다 a 흑백 모드, that 이다, FSTN. 더 위 모드 의 the 편광 회전 90 정도 , that 이다, 그것 된다 a 파란색 모드, 및 the 효과 의지 있다 있다 더 좋아진다.
As can be seen from the figure, the liquid crystal display is a liquid crystal cell made of upper and lower two sheets of conductive glass. The cell is filled with liquid crystals, and the periphery is sealed with a sealing material-a plastic frame (보통 an 에폭시 수지). 양 측면 의 the cell are sealed. 편광 부착.
The interval between the upper and lower glass plates in the the liquid crystal cell, which is generally referred to as the cell thickness, is generally sever micrometers (man's accuracy diameter is tens of micrometers). The inside of the the upper and lower glass plates, corresponding to the display pattern portion, is coated with a transparent conductive oxide-tin oxide (ITO) conductive film, ie, a display electrode. The Role of the the 전극 is 주로 to make the 외부 전기 신호 통해 그것 to the 액체 결정.
The 전체 디스플레이 면적 내부 the 유리 pane in the 액체 결정 셀 is 덮인 with an alignment layer. The role of the alignment layer is to align the 액체 결정 분자 in a specific direction. This alignment layer is 보통 a thin layer 의 유기 폴리머 and is 처리된 의해 문지르는; it can also be prepared by 진공 증발 의 a 실리콘 산화물 필름 at an angle on the 유리 표면. .
The TN-type liquid crystal display is filled with a positive nematic liquid crystal. The orientation of the liquid crystal molecules is such that the long rod-type liquid crystal molecules are arranged in a fixed direction parallel to the glass surface, and the direction of the the long axis of the the molecules is along the the orientation treatment direction. The 방향 방향 의 상단 및 하단 유리 표면 are 수직 to 각 other, 그래서 that the 방향 of the 액체 결정 분자 in the box is 점차적으로 점차적으로 왜곡 in the 방향 수직 to the 표면 의 유리 시트, 및 the 유리 시트 is 뒤틀린 의해 90 정도 에서 그 상단 유리 시트 에 아래 유리 시트 (참조 the 그림 아래). 그것 이다 그 원점 의 그 그 트위스트 네마틱 LCD 이름.
In fact, the 액체 결정 분자 가까운 the 유리 표면 없다 완전히 평행 the 유리 표면, 그러나 오히려 있는 at a 확실한 각도 to 그것. This angle is called the pretilt angle, which is generally 1 degree ~2 degree .
둘 편광자 아르 각각 부착 에 바깥쪽 측면 의 the 유리 시트 in the 액체 크리스탈 cell, and the polarization 축 의 the 둘 편광자 are 평행 to each other (the normal black type is white on a black background) or are orthogonal to each other (a normally white type is a black symbol on a white background). The orientation direction of the surface of the 액체 결정 cell is 평행 또는 수직 to each other. 편광자 are 일반적으로 가공된 by 폴리머 플라스틱 필름 under certain process conditions.
대부분 의 무엇을 우리 보통 보는 이다 a 역형 액체 결정 디스플레이, which 있다 a 반사 시트 뒤에 the 낮은 편광자. In this way, light is incident and observed on the same side of the cell.
디스플레이 방법
LCD has a 다양성 of display methods: reflective, transmissive and translective. A reflective plate is attached behind the bottom polarizer of the reflective LCD. It is generally used outdoors and in well-light offices. The bottom polarizer of a transmissive LCD is a transmissive polarizer, which requires the continuous use of a backlight, and is generally used in a poor light environment. The transflective LCD is between the above two. The bottom polarizer can partially reflect light and generally has a backlight. when the the light is good, the backlight can be turned off. when the light is poor, the backlight can be lit using the LCD.
LCD 디스플레이 is 또한 분할 into positive and negative. 양수 LCDs have black letters on a white background and are best viewed in reflective and transflective LCDs; negative LCDs are shown in black on white and are generally used in transmissive LCDs. with a backlight, the fonts are clear and easy to read.
역광
투과형 및 반투과형 LCDs generally need to add a backlight source. The placement of the backlight according to the actual situation below introduces sever common backlight sources:
전계 발광 (EL): EL 백라이트 are thin, 경량, and 방출 빛 균일하게. It can be used in different colors, but it is most commonly used in LCD white backlights. EL backlight power consumption is low, only the voltage of 80-100VAC, through the the transformer to 5V, 12V or 24VDC conversion. The EL backlight has a half-life of about 2000-3000 hours.
빛 발광 다이오드 (LEDs): LED 백라이트 are 주로 사용 문자형 모듈. 장수 than EL (최소 5000 시간), 강하게 빛, 그러나 크게 에너지 소비. As a solid state device, it 사용 5VDC 직접. The LCD is 일반 정렬 직접 뒤에 the LCD, and the 두께 is 증가 5mm. The LEDs can emit different colors of light, the most common being yellow-green light.
차가움 음극 형광등 램프 (CCFL): The CCFL can provide low power and bright white light. It emits light from a cold cathode fluorescent tube, and the light is evenly dispersed in the window area by a diffuser. The side backlight has a small size and low power consumption, but the CCFL needs a transformer to supply {{}}VAC. It is mainly used for graphic LCDs and has a lifetime of 10,000 to 15,000 시간.
TN and STN are two types of liquid crystal displays. The liquid crystal of the the TN display is by 90[deg.] in the the liquid crystal cell and is generally used for low-channel LCD products.
그만큼 액체 결정 표시 의해 the STN is by 180 정도 360 정도 in 액체 결정 셀. 크게 비틀기 각도, 가파르게 the 전자광학 곡선 및 the 더 가까운 V 켜기 및 V 끄기 값. 할 수 있 있거나 생산을 위해 생산 의 32 또는 더 LCD 제품.
LCD 투시
The point of view is simply the angle at which the display pattern can be see clear. it is determined by the rubbing direction of the alignment layer and cannot be changed by roating the polarizer. the angle of view is named after the hour hand, such as 6:00 viewing angle, 12:00} viewing angle, and so on. The 6:00 viewing angle means that the LCD in the area from the the 6 o'clock to the the normal direction of the hour hand is ideal; the 12:00 viewing angle is the the ideal display of the the 12 o'clock corn to the normal direction.
The LCD's viewing angle is determined by the position of the LCD display on the instrument. For example, a calculator is 보통 배치 on the table or on the hand, and the LCD is made at the 6:00 viewing angle. Some instruments have an LCD screen mounted below the the line of the the human eye and are Generally made at a viewing angle of 12:% 7b{3}}. The clock on the the car is generally mounted on the right side of the driver, making the best viewing angle of 9:{00.
