How to determine if the LCD screen is leaking light seriously?
Date:2025-12-11
The core principle for determining whether the LCD screen is severely leaking light is whether it has caused significant and undeniable interference to your viewing experience in your actual daily use scenarios. Leakage is a physical phenomenon that cannot be completely avoided, and the key is whether its degree is "acceptable".
Here is a complete guide from easy to difficult, from testing to practical judgment, to help you make an objective assessment.
Step 1: Conduct standard testing (to obtain objective information)
Prepare the environment: In a completely dark room (out of sight), let your eyes adapt to the darkness for a few minutes.
Display content: Display a pure black image on the screen (you can search online for "pure black image" for full screen display). Do not use the shutdown state test, as some TVs/monitors will completely turn off the backlight after shutdown and cannot be detected.
Observation and preliminary judgment:
Normal or slight light leakage: There is a uniform and weak halo at the edge of the screen (usually white or light yellow), especially at the corners or sides (side in backlighting is common). At a normal viewing distance from the front, it feels like the screen is not dead black, but dark gray.
Possible serious signs: asymmetric, overly bright, bundled light spots (such as a prominent bright area in the bottom right corner), or bright bands running through the edge of the screen. When taking photos with a mobile phone (the camera exposure is more sensitive than the human eye), if there are glaring light clusters or obvious beams in the photo, it also indicates that the problem is prominent.
Step 2: Key judgment criteria (from phenomenon to conclusion)
Please judge based on the following four criteria, the more they meet, the more serious the problem is:
Judging dimensions | Acceptable (mild light leakage) | Possible serious (requiring attention) | Usually severe (recommended for after-sales service) |
1. Uniformity and symmetry | The edge leakage is uniform, symmetrical, and presents a natural transition. | The edge leakage is uniform, symmetrical, and presents a natural transition. | Isolated and concentrated bright spots or beams appear (such as "chrysanthemum shaped" or "lightning shaped" light patterns). |
2. Daily content interference | It can only be detected in the fully black test screen, and cannot be felt at all while watching movies, working, or surfing the internet. | When watching a movie with black borders on top and bottom, one can clearly see that the black borders appear gray and white, which distracts attention. | In normal movie and game dark scenes (such as night sky and darkroom scenes), uneven background brightness and halo can be clearly seen, which destroys immersion. |
3. Visual angle influence | It is not obvious when viewed from the front and requires deliberate observation from the side to see the light leakage. | The light leakage area can be easily detected at a normal viewing distance from the front (such as 2-3 meters for TV and 50-70 centimeters for monitor). | Under any angle and normal viewing, light leakage is very noticeable and cannot be ignored. |
4. Impact of ambient light | After turning on the room lighting (even a small night light), the leakage of light is basically or completely invisible. | Under brighter ambient light, the impact of light leakage still exists. | Even indoors during the day, uneven brightness can still be seen when displaying dark content. |
Step 3: Special Reminders for Different Device Types
For ordinary side entry/straight down screens without partition control:
High expectations: Light leakage is a common phenomenon in this type of product. As long as it does not affect daily viewing, it belongs to the "industry norm", and manufacturers usually do not provide warranty.
Focus on "interference": strictly judge according to item 2 (daily content interference) in the table above.
For high-end screens with partition controlled lighting (such as Mini LED):
Distinguish between "light leakage" and "halo":
Leakage: Edge bleeding that occurs when displaying large areas of pure black static images, which is a structural issue.
Halo: A small halo that appears around bright objects when displaying high contrast dynamic images such as "stars in the dark" and "white subtitles". This is the physical limit of partition control technology itself (lateral scattering of light), not a fault. The more partitions there are, the better the halo control.
Judgment criteria: The main focus should be on whether the halo control is at an excellent level (such as being recognized as performing well in the evaluation), and whether the static light leakage is abnormally prominent.
Final decision list
Belonging to normal, it is recommended to relax:
Only a uniform halo is visible in the fully black test image.
Under daily use (turning on ambient lights, watching normal content), there is no sensation at all.
This is the common state of the vast majority of qualified LCD screens.
At a critical point, a comprehensive balance needs to be made:
I can notice the black border while watching a movie, but it's tolerable.
The device itself is inexpensive and does not have partition light control function.
You can try reducing screen brightness and turning on a little ambient light to significantly improve the experience.
Serious, it is recommended to contact after-sales/return/exchange:
When watching videos and games in daily life, light leakage continues to distract your attention and disrupt immersion.
Obvious and asymmetric bright spots or beams appear, which are usually due to assembly defects or component compression.
You discovered it within 7 or 15 days after purchase and are very concerned about it (new products should enjoy stricter standards).
After your rational judgment, it has exceeded your reasonable expectations for the image quality of this device.
The most important summary
Don't become a 'test chart police'. Screens are bought for use, not for finding flaws under extreme conditions. The final criterion for judgment should be: Does it make you feel uncomfortable in your actual usage environment?
If the answer is' yes', even if the test results are 'theoretically not the most severe', you have ample reason to seek after-sales solutions because the value of a product lies in providing a good user experience. If the answer is' no ', then please enjoy your device with peace of mind, without worrying about minor flaws that only exist under specific conditions.
AUO LCD:https://www.auo-lcd.com/products/auo-lcd-screen/
