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The RGB color model and screen abnormalities

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The RGB model is derived from the three colors that it uses: red, green, and blue. This model utilizes an addictive approach that combines red, green, and blue colors in various proportions and ways in order to produce a wide variety of colors. This model is utilized in various output devices including cellphone displays, computer displays, TV sets, and video projectors.


The RGB model is classified as a device-dependent model simply because RGB values are reproduced by different devices distinctively. This behavior is mainly due to the fact that the response of the color elements to the individual color levels varies according to the manufacturer. This means that a color element manufactured by one company will detect different levels from a similar element manufactured by another company.

By design, each pixel of an LCD screen is made up of three clusters. Each RGB color- red, green, or blue- is represented by a cluster. Every time an image is processed, a corresponding change occurs in the color composition of the functional dots that display images (pixels). These changes cause the displayed images to change as well.

The RGB produces color through superimposition of the three light beams. These three color beams, usually referred to as the components of a color, can have unique intensity levels.

We are now going to explore the most common pixel abnormalities. An abnormal pixel that displays only black is commonly referred as a dead pixel. On the other hand, an abnormal pixel that displays just white is referred as a hot pixel.

Dead pixels

A dead pixel abnormality is usually caused by transistor defects. When a transistor is stuck in off position (in the case of IPS) or on position (in the case of TN displays), the pixel is affected making it impossible for the part to display anything. Such a pixel gives a black display.

Dead Pixel

Hot pixels

In the case of a hot pixel, the transistor is usually stuck in the on position (in the case of IPS) or off position (in the case of TN displays). This defect causes light to pass through resulting in an only white display.

Stuck pixels

When a transistor is stuck in an on position, the affected pixel is referred as a stuck pixel. This condition can also result from a manufacturing defect. The most common manufacturing defect that causes this condition is improper cutting of the RGB film layer.

Owing to the conditions that cause hot and dead pixels, it is very unlikely for the problems to disappear over time. In most cases, the pixel is affected permanently. On the other hand, the stuck pixel problem is known to disappear over time. You can also fix a stuck pixel by using special software or by applying pressure on the affected pixel.



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