The Differences of LCD and LED

    In modern electronic devices, the display screen is an important interface for human-computer interaction. With the development of science and technology, display screen technology is also constantly improving. Among them, liquid crystal display (LCD) and LED display are two mainstream display technologies. They differ in display principle, performance, application field and cost.

1. Display principle

1.1 Liquid crystal display (LCD)

Liquid crystal display (LCD) is a technology that uses the electro-optical effect of liquid crystal materials to realize image display. Liquid crystal material is a substance between liquid and solid, with the characteristics of fluidity and anisotropy. Under the action of the electric field, the arrangement of liquid crystal molecules will change, thereby changing the transmittance of light and realizing the display of images.

The basic structure of LCD includes two parallel glass substrates with liquid crystal material in the middle. Transparent conductive layers are coated on the two glass substrates as electrodes. By controlling the voltage on the electrode, the arrangement of liquid crystal molecules can be changed, thereby controlling the transmittance of light. In order to achieve color display, LCD also needs to coat color filters on the glass substrate to display color images through red, green and blue filters.

1.2 LED display

LED display (Light Emitting Diode Display, LED for short) is a display technology that uses light-emitting diodes (LEDs) as light-emitting elements. LED is a semiconductor material. When current passes through, electrons and holes recombine in the semiconductor material to generate photons, thereby achieving light emission.

The basic structure of LED display includes LED light-emitting elements, drive circuits and control circuits. LED light-emitting elements are the core part of the display and are composed of a large number of LED lamp beads. The drive circuit is responsible for providing a stable current to the LED lamp beads, and the control circuit is responsible for receiving input signals and controlling the brightness and color of the LED lamp beads.

2. Performance characteristics

2.1 Liquid crystal display (LCD)

2.1.1 Display effect

The display effect of LCD mainly depends on the response speed, contrast and color performance of the liquid crystal material. Generally speaking, LCD has a slow response speed and is prone to afterimage. Contrast and color performance are also limited by liquid crystal materials and color filters, and it is difficult to reach a high level.

2.1.2 Energy consumption

The energy consumption of LCD is relatively low, especially when displaying static images, the energy consumption is even lower. This is because LCD does not need to continuously provide an electric field for the liquid crystal molecules, and only consumes energy when the image changes.

2.1.3 Lifespan

The lifespan of LCD is relatively long, generally reaching tens of thousands of hours. This is because the liquid crystal material has good stability and is not easily affected by the external environment.

2.1.4 Viewing Angle

The viewing angle of LCD is limited by the arrangement of liquid crystal molecules and is generally small. When viewed at different angles, the image may have color distortion or brightness changes.

2.2 LED display

2.2.1 Display effect

The display effect of LED display mainly depends on the brightness, contrast and color performance of LED lamp beads. LED lamp beads have a fast response speed and are not prone to afterimages. The contrast and color performance are also good and can reach a very high level.

2.2.2 Energy consumption

The energy consumption of LED display is relatively high, especially when displaying dynamic images, the energy consumption is higher. This is because LED lamp beads need to continuously consume energy to maintain light emission.

2.2.3 Lifespan

The lifespan of LED display is relatively short, generally reaching thousands to tens of thousands of hours. This is because the stability of LED lamp beads is poor and is easily affected by the external environment.

2.2.4 Viewing Angle

The viewing angle of LED display screen is large, which can reach 180 degrees. When viewed at different angles, the brightness and color of the image change little.

III. Application Fields

3.1 Liquid Crystal Display (LCD)

Due to its low energy consumption, long life and good display effect, LCD is widely used in various electronic devices such as mobile phones, tablet computers, laptops, monitors, TVs, etc. In addition, LCD can also be used in outdoor billboards, public information display screens and other occasions.

3.2 LED Display

Due to its high brightness, large viewing angle and good display effect, LED display screens are widely used in outdoor billboards, large stadiums, stage backgrounds and other occasions. In addition, LED display screens can also be used in traffic lights, car taillights and other occasions that require high brightness display.