LCD display/TV missing dots & burn-in checker | ZeroTools

The display dead pixel checker is designed as an auxiliary tool to make it easier for users to visually check the state of pixels on LCD and OLED screens.

This tool sequentially provides a single-color background of 8 colors in total: white, black, red, green, blue, yellow, cyan, and magenta.

By independently providing the three primary colors of light (RGB), it becomes easier to individually observe the behavior of the subpixels corresponding to each color filter.

Furthermore, by using the intermediate colors of yellow, cyan, and magenta, lighting abnormalities in states where multiple subpixels are combined are highlighted.

The white pattern is an aid in visually identifying defects in pixels that should block light, while the black pattern helps identify defects in pixels that should not transmit light, though actual physical brightness and true black depend on the device and OS color management.

In this way, by filling the entire screen with a single color component, we adopt an approach that makes dots (pixels) reacting differently from the surrounding normal pixel groups easy to perceive as a difference in contrast by the human visual system.

However, this tool does not have any function to automatically scan the state of pixels through software to detect abnormalities or highlight the corresponding locations on the screen.

It is also impossible to attempt to repair dead pixels by sending special voltage signals to the pixels. It is specialized in deploying colors on the drawing area of the browser and supporting judgment through the user's vision and cognition.

In order to observe the display state of the screen as accurately as possible, the preparation stage before launching the tool and starting the test is of great significance.

First of all, physical dirt such as fine dust, fingerprints, and splashes attached to the surface panel of the display often look very similar to unlit pixels (dark spots) or pixels that reflect surrounding light and shine in different colors (bright spots).

Therefore, it is necessary to carefully wipe the entire screen in advance using a dedicated microfiber cloth or display cleaner. In addition, the indoor lighting environment also has a great influence on how the details of the screen look.

In environments where ceiling lights or outside light from windows reflect directly on the screen, the reflected light becomes visual noise depending on the surface treatment of the panel (non-glare or glare), making it extremely difficult to identify minute dots or very slight color unevenness.

Furthermore, the hardware settings for the brightness and contrast of the backlight of the display itself greatly change the visibility of abnormalities for specific colors.

Do not confuse RGB color values with the physical maximum brightness of the monitor. Because this tool is a web application running on a browser, it is technically impossible to directly intervene in the brightness or color settings of the connected monitor or perform brightness calibration.

Therefore, it is recommended that the user manually adjusts the display settings of the OS or the operation menu of the monitor itself to the standard brightness used daily, or the optimal state where abnormalities are easiest to check, before performing the visual confirmation work.

When scanning every corner of a screen, having UI elements remain visible can be a hindrance. Therefore, this tool implements UI controls and keyboard shortcuts to maintain visual concentration.

When an operation such as moving or clicking the mouse pointer is performed, an operation panel indicating the current color and controls is displayed, but it automatically fades out and hides 3 seconds after input stops, leaving the screen filled with a single color.

For switching colors, you can advance using the right arrow key, Space key, or Enter key, and retreat using the left arrow key or Backspace key.

This allows you to continuously check the reaction of pixels in different colors. It also features shortcuts such as toggling full-screen display by pressing the F key and immediately ending the test using the Esc key.

Note that the function to start the test uses the container reference immediately upon activation; if it is unmounted, it does not automatically go full screen.

While the F key can request full screen for a mounted container, this request may also be rejected by the browser.

In order to distinguish pixels that behave clearly differently from surrounding pixels against a highly pure single-color pattern deployed on the screen, it is a great help to observe while understanding the characteristics of color combinations.

For example, when the entire screen is set to black, there may be cases where extremely small dots that continue to shine brightly in red, green, blue, etc.

can be seen in places that should normally completely block the light of the backlight and sink into darkness. These are generally called bright spots (always-on pixels), indicating a behavior where a specific subpixel is always in a light-emitting state due to a transistor defect or the like.

Conversely, when the entire screen is set to white or other bright colors, places that do not emit light and sink as black dots while the surroundings are emitting light uniformly are recognized as dark spots (always-off pixels).

When moving your gaze from one end of the screen to the other using this tool, instead of vaguely looking at the entire screen at once, you will find it easier to notice slight incongruities if you virtually divide the screen into several small blocks and let your gaze crawl as if filling them in while slightly shifting your focus.

However, the appearance is also strongly affected by the viewing angle characteristics of the panel (changes in appearance from top, bottom, left, and right), so by changing the angle slightly and looking at it diagonally instead of looking at it vertically from directly in front, you may be able to see the spread of uneven brightness, color unevenness, and phenomena that look like light leakage at the edges more clearly.

In order to fully utilize the physical display area of the display and completely eliminate visual noise such as OS taskbars, browser address bars, and tabs, this tool is designed to call the Fullscreen API, a standard web technology.

Triggered by the operation of the start button on the screen or the F key, it asynchronously requests the browser to transition to full-screen mode.

However, this Fullscreen API has very strict security restrictions to prevent malicious websites from continuously occupying the screen against the user's intent, and a request does not always result in a full screen.

A full-screen request requires a transient user activation triggered by the user's direct and intentional operation (mouse click or keyboard input), and depending on browser specifications, user permission settings, or OS-side restrictions, the request can be implicitly rejected.

Additionally, if the initial element is not yet mounted, the full-screen request itself will not be made. If the transition to full-screen mode does not occur even after pressing the start button, browser or embedded environment restrictions may be affecting it.

Note that exiting full-screen mode alone does not necessarily end the ongoing process. Even if the transition to full-screen display fails, the sequential color switching function of the tool itself operates normally within the browser's window area, so it is possible to continue the visual confirmation work in a state close to that by maximizing the window.

The appearance and visual discomfort obtained by observing the patterns displayed on the screen using this tool are purely subjective perceptions by the user of the display state of the screen at that specific point in time, and do not objectively confirm hardware failure of the display.

Display panels such as liquid crystal displays (TN, IPS, VA, etc.) and OLEDs have diverse driving methods and physical hardware structures, and it is not the case that exactly the same appearance and characteristics can be obtained with all panel methods.

Uneven brightness or phenomena resembling light leakage seen around the four corners or edges of the screen, or phenomena where contents displayed for a long time in the past can be seen faintly remaining, may be characteristics within the specification range of the product, or may be simply due to aging deterioration.

This tool does not have functions such as performing advanced diagnosis of burn-in or accurately measuring pixel response speed and brightness to make product quality assurance judgments.

The tool cannot be used for monitor warranty judgment or ophthalmic diagnosis. Furthermore, clear criteria for being recognized as dead pixels or bright spots (allowable number, position within the screen, continuity of multiple defects, etc.) and conditions for panel replacement or repair based on warranty are independently defined by each display manufacturer and distributor.

The results of visual confirmation using this tool cannot be used to immediately conclude that the display is defective, or as a direct basis for requesting warranty support or free repair from the manufacturer, and the final state determination is entirely left to the hardware manufacturer's criteria and judgment.