The Operating Principle Of LCD Speedometer

  • Segment LCD, or segment LCD, is one of the LCD products, but in the LCD industry, it is generally called pattern LCD, pen segment LCD, monochrome LCD, etc. It is used to distinguish it from the dot matrix LCD screen, so the segment LCD is not a strict expression or classification.

    The segment code liquid crystal name originated from the early application of LCD screens, mainly to replace LED digital tubes (composed of 7 pen segments, used to display numbers 0-9), such as calculators, lcd speedometer, etc. It is a number and is relatively simple. Nowadays, non-dot-matrix LCD displays are generally called segment LCDs.

    TN type LCD screen usually has three modes: full transmission, semi transmission and reflection. The liquid crystal will not actively emit light, and an external light source is required. The light source of the translucent liquid crystal comes from the back of the liquid crystal; the light source of the reflective liquid crystal comes from the front of the liquid crystal and is reflected by the polarizer of the liquid crystal screen to the observer's eyes; the translucent liquid crystal is between the two, and there is light from behind the liquid crystal There is also reflected forward light. Therefore, the full-transmission liquid crystal requires the use of a backlight, the reflectivity does not require a backlight, and the transflective liquid crystal can use a backlight or not. It is impossible to observe the display in the dark on the LCD screen without backlight. pulsar speedometer using segment liquid crystal has several characteristics such as low price, low driving cost, simple operation and free format, so it is widely used.