Teach you how to understand LCD screen product specifications
In the process of selecting LCD screen products, we usually provide customers with a product specification she
In the process of selecting LCD screen products, we usually provide customers with a product specification sheet that meets the parameters for their reference. The product specification sheet for LCD screens is usually in full English, which covers all the parameters and dimensional drawings of the LCD screen product. What parameters need to be focused on? Below, we will help you quickly get started from two aspects: the key parameters of the LCD screen specification book and the analysis of the product specification book.
1、 There are many key parameters in the LCD screen specification book, but for the initial stage of user selection, some key parameters need special attention. Size inch: Size is the most basic condition for users to choose a LCD screen, and it needs to match the size of the product's casing. Usually, the selection is based on the target size. In the field of industrial LCD screens, small and medium-sized LCD screens are commonly used, such as 4.3-inch, 5.6-inch, 7-inch, 10.1-inch, 10.4-inch, 12.1-inch, etc., depending on different usage scenarios. The size of the LCD screen is expressed in inches (inches) by the length of the diagonal. Therefore, in the product specification sheet, we need to pay attention to the keyword 'inch'.
Resolution Number of Dots: Resolution refers to the height of the screen pixels, expressed in terms of width * height. For example, 800 * 600, 1024 * 768, and so on. We usually think that the higher the pixel count, the higher the screen definition, but at the same time, we also need to consider the screen size to distinguish whether it is high-definition or not. For example, we believe that a 4.3-inch screen with 800 * 480 resolution is considered high-definition, while a 10.1-inch screen can achieve a high-definition resolution of 1920 * 1200. Resolution is specified in the specification sheet, and we need to pay attention to the keyword Number of Dots.
LCD type: The main types of LCD panels include TN panels, IPS panels, VA panels, and so on. Users need to choose the appropriate LCD panel based on their needs and budget. For example, terminal products have high requirements for screen viewing angle, so IPS panels need to be selected to achieve a 178 degree full viewing angle effect. We need to pay attention to the keyword LCD type in the specification sheet. Screen Brightness: Screen brightness usually refers to the brightness generated by the backlight of the screen, usually measured in cd/m ² or nit. Generally, in indoor environments, a brightness of around 300cd/m ² is sufficient to meet usage needs. However, in outdoor environments with strong lighting, higher brightness backlighting is required for normal display, typically requiring 500cd/m ² or more for normal display. In the specification sheet, we need to pay attention to the keyword Brightness.
Viewing Direction of LCD Screen: The viewing angle of a LCD screen refers to the visible range of the screen that can still be clearly displayed when the user observes the screen from the horizontal position on the left and right, as well as the vertical position on the top and bottom. The viewing angle needs to be selected according to the product's usage environment. For example, the screen of an instrument needs to display normally at all angles, so a full view LCD screen needs to be selected. IPS panel is currently the most widely used full view LCD panel on the market. The TN panel will have a grayscale inversion perspective, and the keyword on the specification sheet is Gray Scale Inversion Direction. The grayscale reversal angle of a typical TN panel is in the 6 o'clock direction, which means that when looking at the screen from bottom to top, the brightness and color of the image will be reversed, resulting in a relatively poor display effect.
2、 Example Analysis of LCD Screen Product Specification
Through the previous introduction of some key parameters in the specification book, today we will further deepen our understanding through the analysis of examples. Let's take our 19 inch product G190EG01 V1 from AU as an example for analysis.
1.The parameter table on the first page of the Basic Parameter Table Specification is the most important table, as shown in the following figure. It covers all the parameters of the preliminary selection, and whether this model is suitable can be preliminarily judged in this table. The table includes the LCD screen size, resolution, panel type, viewing angle, etc. that we previously introduced. Special attention should be paid to the Driver IC and Interface type here. Because these two parameters are related to whether the motherboard interface and driver software of the customer's terminal product match the screen, or whether they need to be changed later. In addition, it is important to pay attention to the aspect ratio of the LCD screen. This parameter will not be directly written into the specification sheet and needs to be calculated. We first find the parameter ActiveArea (W × H), which means the size of the visible area of the screen. As shown in the figure below, the visible area size of the model is 376.32 (H) x 301.06 (V). Therefore, the aspect ratio of the screen can be calculated to be 5:4. It should be noted that the aspect ratio of LCD screens of the same size may not be uniform, for example, a 19 inch LCD screen has a 5:4 ratio. Choose the appropriate aspect ratio according to the requirements. If you have certain requirements for the operating temperature of the screen, you also need to pay attention to the parameter Operating temperature, which is the working temperature.
2. Dimensional and structural drawings
In the specification sheet, the dimension diagram is also the most important focus that users need to pay attention to. The dimension diagram contains many important information, such as the appearance size of the screen, the size of the display area, the thickness of the screen, the size and length of the FPC, as well as the PIN definition table of the interface, the circuit diagram of the backlight, etc. These dimensions and parameter information are very important for the overall structural design of the product and are worth careful comparison and research by users.
3. Optical Characteristics Analysis Table
The optical characteristic analysis table is located in the middle of the specification sheet and includes some color properties of the LCD screen. After initial selection confirmation, users will pay more attention to these attribute values, as shown in the following figure.
Brightness backlight brightness: usually takes the middle value, and the brightness of this model is 350cd/m ². If the backlight brightness is not sufficient, it can be customized.
Viewing Angle: Taking the middle value, this model has a viewing angle of 80 degrees in all four directions, including up, down, left, and right, which can be defined as a full view angle.
Contrast Ratio: Take the middle value, this model is 1200:1. This contrast ratio is considered high in LCD screens. The contrast ratio of LCD screens is usually around 800:1 to 1200:1, with a maximum of 1500:1.
Response Time: It is divided into the rise time Tr and fall time Tf of the response, and the response time we usually refer to the sum of the two. The response time of this model is 10+20=30ms, measured in milliseconds.
NTSC Ratio screen color gamut: Here we will introduce the color gamut, which refers to the color range that LCD screens can display. The higher the value of color gamut, the wider the color range that the screen can display, and the richer the color presentation. Color gamut is generally expressed as a percentage of NTSC. The color gamut of this model is 60%. Generally, the color gamut of ordinary screens is around 50%, while some high color gamut screens can achieve an NTSC value of around 80%.
