What Do Resolution, Brightness, and Contrast of a Liquid Crystal Display Module Mean?

A liquid crystal display module (LCM, Liquid Crystal Module) is a display component that integrates the liquid crystal panel, driver circuit, and backlight system. The resolution of an LCM represents how many pixels the image contains, brightness indicates how strongly the screen emits light, and contrast reflects the difference between the brightest white and the darkest black.

Resolution: mainly affects the fineness of the picture and the amount of information displayed.
Brightness: mainly affects screen visibility under different ambient light conditions.
Contrast: mainly affects the light-dark gradation and dark detail of the picture.

These three parameters respectively affect fineness, visibility, and layering. When selecting a module, you should not only look at a single value.

Resolution represents the number of pixels in the image

The resolution of an LCM is usually expressed as "horizontal pixels × vertical pixels." A pixel is the smallest display unit that makes up a digital image. In simple terms, it is a tiny dot on the screen that can show changes in color and brightness. According to ISO 9241-302:2008 "Ergonomics of human-system interaction — Part 302: Terminology for electronic visual displays", a display pixel can be understood as the basic element that can independently form image information.

For example:

800×480 resolution contains 384,000 pixels.
1920×1080 resolution contains 2,073,600 pixels.
The total pixel count of the latter is about 5.4 times that of the former.

These figures are obtained by multiplying the horizontal and vertical pixels. They are for reference in module selection and do not directly mean that the actual image quality is necessarily better.

Resolution also needs to be evaluated together with screen size and viewing distance. Pixel density PPI (Pixels Per Inch) refers to the number of pixels arranged within one inch. In simple terms, the higher the PPI, the denser the pixels per unit area. At the same 1920×1080 resolution, a smaller size usually has higher pixel density. In addition, interface bandwidth, graphics output capability, and software adaptation must also match the resolution.

Data source: Terms related to pixels and display resolution refer to ISO 9241-302:2008; the total pixel counts and the multiple in the example are calculated from the horizontal and vertical pixels.

Brightness represents how strongly the screen emits light

The brightness of an LCM represents the luminous intensity per unit projected area in a specified direction. The common unit is cd/m², also called "nit." In simple terms, the brightness value reflects how bright the screen looks; 1 nit equals 1 cd/m². The International Commission on Illumination, in CIE S 017:2020 "ILV: International Lighting Vocabulary", defines luminance as a photometric quantity related to "the luminous intensity in a given direction and the projected area," which is also an important basis for display measurement.

For example, compared with a module with a nominal brightness of 300 cd/m², a module with a nominal brightness of 500 cd/m² has a nominal brightness about 66.7% higher. However, this calculation only reflects the difference in parameters and does not equal a visual improvement under all conditions. Indoor instruments, outdoor terminals, and vehicle-mounted devices face different ambient illuminance, so their required brightness is also different. The relevant values are for reference only.

According to IEC 61747-30-1:2012 "Liquid crystal display devices — Part 30-1: Measuring methods for liquid crystal display modules", optical performance should be evaluated under specified measurement positions, directions, and environmental conditions. Here, "optical performance" refers to measurable indicators related to display quality, such as brightness, contrast, uniformity, and chromaticity.

The main factors affecting the actual measured brightness of an LCM include:

Backlight power and backlight system status;
Operating temperature and ambient illuminance;
Transmittance of the touch panel and cover glass;
Measurement position, viewing direction, and displayed content.

Therefore, when comparing 金鹏 liquid crystal display modules, you should confirm whether the brightness is a typical value, a minimum value, or a value measured under specific conditions.

Data source: The definition and unit of brightness refer to CIE S 017:2020; the optical performance measurement conditions of LCMs refer to IEC 61747-30-1:2012.

Contrast represents the difference in light-dark gradation

The contrast of an LCM usually refers to the ratio of white-field luminance to black-field luminance, often written as 500:1 or 1000:1. "White field" is the state when the screen displays a white test pattern, and "black field" is the state when the screen displays a black test pattern. The International Committee for Display Metrology, in its IDMS "Information Display Measurements Standard", emphasizes that clear test patterns and measurement conditions should be used to evaluate display contrast performance, so as to reduce differences caused by ambient light and test methods.

Assuming a white-field luminance of 500 cd/m² and a black-field luminance of 0.5 cd/m², the static contrast ratio is 500 ÷ 0.5, that is, 1000:1. Static contrast ratio is the ratio obtained by directly comparing white-field luminance with black-field luminance under fixed test conditions. This example is only used to explain the calculation method; actual results are affected by the following factors:

Liquid crystal display mode;
Degree of backlight light leakage;
Viewing angle and ambient lighting;
Accuracy of the measuring instrument and the test method.

The higher the contrast, the more favorable it is generally for presenting dark details and text edges, but it cannot be evaluated independently of the usage scenario. According to ISO 9241-307:2008 "Ergonomics of human-system interaction — Part 307: Analysis and compliance test methods for electronic visual displays", visual performance also needs to be judged comprehensively with indicators such as luminance uniformity, reflection, chromaticity, and viewing direction. Here, luminance uniformity refers to whether the brightness of different areas of the screen is consistent, and chromaticity is used to describe the characteristics of displayed colors.

How to select parameters for 金鹏 liquid crystal display modules

When selecting a 金鹏 LCM, it is recommended to first determine the interface information amount and viewing distance, and then confirm the resolution:

If the product mainly displays numbers, icons, and menus, priority can be given to interface adaptation and operating stability.
If images or fine curves need to be displayed, more attention should be paid to higher pixel count and pixel density.
Also confirm whether the main control platform, interface bandwidth, and software support the target resolution.

Second, determine the brightness according to indoor, strong-light, or outdoor environments, and check the test conditions. For applications with high requirements for dark-level gradation, you should also check contrast, black-field performance, and viewing angle data to avoid judging display quality only by the nominal peak value.

金鹏 recommends that customers conduct actual measurements during the sampling stage using the final cover glass, touch structure, and complete device housing, and verify under the target temperature and ambient light. In the comprehensive evaluation, attention should be paid to:

Resolution, brightness, and contrast;
Interface type and complete device power consumption;
Operating temperature and viewing angle;
Backlight and module service life.

Resolution, brightness, and contrast are core indicators of an LCM, but they cannot replace actual testing in the complete device environment. The data in this article are principle examples and are for reference only. Specific parameters are subject to the product specification sheet and the actual test report.