With the development of optoelectronics and semiconductor technology, the flat panel display is also flourished, and in many flat panel displays, the liquid crystal display (LCD) due to high space utilization efficiency, low power consumption, no radiation and low electromagnetic interference, and many other superior features, has been applied to all aspects of production and life. 
In the assembly process of the liquid crystal display, due to the area of the active area (AA) of the display panel (i.e. liquid crystal panel) manufactured by each panel manufacturers are different, the compatibility of the mechanism frame for press-assembling the liquid crystal panel and the backlight module together is low.  For example, the area of the AA of the display panel manufactured by the A manufacturer is greater than the area of the AA of the display panel manufactured by the B manufacturer, so that when use the mechanism frame for press-assembling the display panel manufactured by the B manufacturer to press-assembling the display panel manufactured by the A manufacturer, the edge of the AA of the display panel manufactured by the A manufacturer will be occluded by the mechanism frame, resulting in the incomplete of the picture displayed by the LCD assembled by the display panel manufactured by the A manufacturer.