01An Image Is Actually Composed of Many Pixels
The photos, text, and game graphics you see look like a single continuous image. But if you zoom in on the screen many times, you'll find it's actually composed of numerous very small dots.
These small dots are called pixels (Pixel). Screens control the brightness and color of many pixels to piece together the final image we see.
Complete Image
Looks like one whole picture from a distance
When Magnified
Can be seen as individual pixels
02How Does One Pixel Create Different Colors?
A pixel in many color displays can usually be further divided into smaller red, green, and blue subpixels, known as RGB.
03How Do LCD and OLED Emit Light?
Different types of screens use different methods to control light. For beginners, it's worth understanding the difference between LCD and OLED.
LCD Liquid Crystal Display
LCD pixels themselves are usually not independent light sources. They mainly use backlight, then control the final light through liquid crystal and filter structures.
OLED Organic Light Emitting Diode Screen
OLED subpixels can emit light on their own, without needing to rely on a unified backlight layer like traditional LCDs.
04How Are Images from the Computer Sent to the Screen?
Screens don't automatically know "what should be displayed now." The computer needs to prepare image data first, then send this data to the display device through the display system.
Program Prepares Content
Such as game scenes, text, or images
Graphics System Generates Image
GPU or other graphics units participate in generating frame data
Display Signal Transmission
Transmitted via HDMI, DisplayPort, or internal device connections
Screen Updates Pixels
Display device controls each pixel to present the image
05Why Do Images Appear to Move?
Animations and games don't actually have one image that "moves." Instead, the screen continuously displays one slightly different image after another. Each complete image is often called a frame (Frame).
Continuous rapid display → We perceive the character as moving
06Does Higher Resolution Always Mean Better Image Quality?
Resolution indicates how many pixels there are horizontally and vertically on the screen. For example, 1920 × 1080 means there are 1920 pixels in a row and 1080 pixels in a column.
Fewer Pixels
At the same size, detail representation capability is usually lower
More Pixels
At the same size, can represent more details
But image quality is also affected by many factors such as screen size, pixel density, brightness, contrast, color performance, and panel quality. So you can't judge a screen's quality solely by resolution.
What You've Learned
- Images on screens are composed of numerous pixels.
- Many color screen pixels use red, green, and blue subpixels to combine different colors.
- LCD typically uses backlight, liquid crystal, and filter structures to control light; OLED subpixels can emit light on their own.
- The computer first generates image data, then sends this data to the display device through display connections.
- The display device's internal control circuitry updates pixels based on image data, rather than the GPU directly lighting each pixel.
- Continuous rapid display of different frames makes us perceive the image as moving.
- Refresh rate and game frame rate are not the same concept.
- Higher resolution can usually represent more details, but it's not the only factor determining image quality.
Next Question: We've learned about CPU, memory, storage, motherboard, graphics card, keyboard, mouse, and screen, how do they work together to complete an entire task? Next article: How Do Computer Parts Work Together?