Filter technology and LED backlight technology
Filters are used for two types of installation and usage, one for colored or colorless optical glass used in lenses, which we refer to as filters for clarity. Filters can be divided into black and white photography filters, color photography filters, commonly used black and white photography filters, and special effects filters. Another method is to place the filter in front of the flash to adjust the color tone of all or part of the subject, in order to produce a special color effect.
There are two technologies that can be extended to the filter installed in the flash, namely filter technology and LED backlight technology. Let's take a look at them:
In traditional color filter applications, a pixel is composed of three sub pixels. Each sub pixel of the cash counting machine is controlled by a field-effect transistor to determine the electric field strength of the sub pixel, thereby determining the light intensity passing through each sub pixel and the light energy passing through each sub pixel. Then, the corresponding primary color (red, green, blue) filter is used to obtain the desired sub pixel. According to the function of the visual system, the primary color of each sub pixel is mixed into the color to be represented by the pixel. White backlight modules such as cold cathode fluorescent tubes or LED light sources must be used. In the principle of color mixing, the primary colors are mixed along the spatial axis. The color mixture on the spatial axis is the color that the human eye can see when seeing things. Color mixing is performed by the three sub pixels of R, G, and B on the spatial axis within a range smaller than the human eye's viewing angle.
On the contrary, field sequential technology removes color filters, and each pixel does not need to be separated into sub pixels to form colors. The three primary color light sources are switched in sequence in time, and the transmittance of the liquid crystal pixels is synchronously controlled during the display time of each color light source to form the relative light amount of each primary color and the residual effect of the visual system's light stimulation to form and detect colors. That is to say, changing the original color mixture on the spatial axis to the color mixture on the temporal axis is to quickly switch the three colors of R, G, and B. If the conversion time is shorter than the time that human vision can distinguish, the residual effect of human vision can be utilized to produce color mixing effects.
In contrast, this technology does not use color filters, allowing R, G, and B to quickly change in front of humans, with a large aperture ratio and almost no loss in light utilization, demonstrating an advantage.
In the absence of display efficiency, the maximum gain of an LCD without color filters greatly improves the utilization efficiency of light, theoretically increasing it to three times that of traditional LCDs.
Traditional CCFL is used as a backlight source for LCD displays, and when the backlight source provides a brightness of 8500 nits, the actual output brightness is approximately 800 nits, due to the loss of each component. It also outputs a light intensity of 800 nits. Due to the removal of the color filter, the light efficiency has been tripled. Considering the increase in turn-on rate, RGB LED backlight only needs to provide a brightness of less than 2500 nits, which can provide a light intensity of 8500 nits equivalent to traditional backlight.