This article has detail description on how ViewSonic defines LCD pixel criteria for warranty of LCD flat-panel displays.

ViewSonic is committed to customer satisfaction by providing the highest quality products in the industry. The result is that our LCD displays generally have very few non-performing pixels. For example, an 18" SXGA (1280 x 1024) display has nearly 4 million sub-pixels. A product exhibiting 7 non-performing pixels would equate to an extremely small 0.00018 percent of the total sub-pixels.

(1280 Horizontal Pixels) * (1024 Vertical Pixels) * (3 sub-pixels per pixel) = 3,932,160 sub-pixels

[(7 non-performing pixels) / (3,932,160 sub-pixels)] * 100% = 0.00018%

To ensure the highest performing displays, ViewSonic sets limits as to the allowable number of pixel anomalies. ViewSonic has adopted the following pixel criteria to supplement our existing three-year limited warranty. This policy applies to all ViewSonic LCD displays during the warranty period within Australian region.

FOR ALL LCD Monitors Only

Applicable Models & Period covered

30 days Zero Dead Pixel policy for all ViewSonic LCD monitors.

Terms and Conditions

1. All Standard Terms and Conditions under ViewSonic Limited Three Year Warranty apply.
2. All ViewSonic LCD Monitors found to have a bright dot or a dark dot (please see description below on Pixel Defect Criteria) will be replaced if found to be defective within the period specified below from invoice date.
3. Should your LCD Monitor exhibit a Pixel Defect please contact your reseller.

Table 1

It is possible that any replacement display may also have some non-performing sub-pixels. This should be considered when requesting a warranty exchange.

Table 2: Other defect specifications (Apply to any LCD monitors)

Acceptable Criteria:

These acceptable criteria are applied throughout our LCD monitor range within 3 years from purchase. (Effective Date: purchase from our authorized distributors after 1 st of Aug, 2005)

For LCD TV only

If your Viewsonic N90 Series & VT76 Series LCD TV has more than 2 Bright pixels within 30 days of purchased, please return to the point of purchased for exchange.

For ALL-IN-ONE PC only.

ViewSonic guarantee that the display performance will operate with no more than three(3) improperly operating pixel within the warranty period.

Explanation

A pixel or picture element, is composed of three sub-pixels in the primary colours of red, green, and blue. At each pixel position in an AMLCD (active matrix liquid crystal display) flat screen monitor, three cells of liquid crystal material form the red, green and blue sub-pixels that together allow the full range of colors to be displayed. Individual transistors are arranged in an array on the rear glass to control each sub-pixel. An anomaly on any one of these individual transistors will cause a bright or dark pixel to appear. These anomalies generally occur only during manufacturing, and additional bright or dark pixels should not appear over time.

The allowable number of non-performing pixels has a direct impact on the yield of the process. If the industry attempted to set a zero standard, the current manufacturing yield would be so low that the cost of an LCD display would be many times higher than it is today. Luckily, most customers and applications are tolerant of a low level of non-performing pixels and prefer the lower cost that the existing standards allow.