The human eye sees an object and can see its colors because the light it emits, or light from its surface, bounces off, enters the eye, forms the image above the visual retina of the eyeball base. Light stimulates photoreceptors on the visual retina; the information that photoreceptors perceive will be transmitted by the nervous system to the brain, producing vision.
There are two types of photosensitive cells. A rod-shaped cell is relatively sensitive to light and dark; the other cone cells are relatively sensitive to the color of light. Of course, the light also has to be at a certain luminance to be perceived. Even with the moonlight, landscapes like houses, trees, etc., in our sight, wanting to define their colors clearly is not easy.
Physical knowledge tells us that light is a kind of electromagnetic wave, the light of different colors with different wavelengths. Electromagnetic waves that are visible to the human eye are called visible light. The longest visible light is red light; visible light with the shortest wavelength is purple light. Light with longer wavelengths of red light is called infrared, light with shorter wavelengths than purple light is called ultraviolet. For the human eye, infrared and ultraviolet rays are light that the human eye cannot see.
Right from the seventeenth century, scientists discovered the phenomenon of chromatic aberration and mixing of light. They shone a beam of white sunlight onto a glass prism. After passing through the prism, the light is divided into seven types of light in order: red, orange, yellow, green, blue, indigo, purple. Conversely, by stacking these seven types of colored light, they will turn into white light. Therefore, to conclude, sunlight is a type of light in mixed colors.
The human eye’s subjective perception of colored light is not entirely consistent with physics’s objective analysis. This difference is called an illusion. For example, the white light we see may be due to the mixture of the seven types of colored lights mentioned above; it could also be due to the three types of pink, yellow, and indigo mixed-light, even probably due to two types of mixed indigo and yellow light. There can be multiple variations of white light, but the results are all white. The subjective feeling of the human eye that cannot clearly distinguish white light is due to which types of colored light are mixed; it is only possible through chromatographic prisms to determine the white light’s composite composition.
White light can at least use two types of superimposed color light. If we want to recreate the boundless world with colorful colors, thousands of thousands of thousands of bright colors, we can also use two basic types of bright colors to overlap. After many experiments and studies, scientists have concluded: using two basic types of colored light in different intensity combinations can reproduce many types of colored light.
Scientists use three red, green, and blue light as the primary color to determine the three primary colors’ basic content. All colors in nature can use the three primary colors according to a certain percentage that get. The three primary colors of red, blue, and indigo are independent of each other, any one of which cannot be mixed with the other two primitives; The proportions in a mixture of three primary colors can determine the saturation and tonality of the mixed color.
Based on the principle of three primary colors, scientists have found a method of transmitting colors in color television. Want to transmit and reproduce very different colors in nature, with a richer range of colors.
Pre-broadcast television signals have decomposed the colors of scenes into three primary colors with different ratios. After modulation by high-frequency radio waves, three types of original color-coded and other signals such as sound, luminance, frequency sweep, etc., are broadcast into the air through the transmitting antenna.
After receiving the TV station’s signal, color TV proceeds to split and decode the television signal. After obtaining the three original colors with different proportions, put them into the three red, green, and blue cathode electronic guns of the display light, respectively. Electrons of each emitted electron tube split apart and shot at the reciprocal red, green, and blue fluorescent powder points. The distance of these three fluorescent powder points is very close; the human eye cannot discern those three points; only their mixed color can be seen.
When you turn on the power switch of color television, the image is visible on the fluorescent screen. You close to it and look closely with the magnifying glass. You will notice that there are many rectangular colored light pieces; every three pieces make one. The group leaned together to form a square. There are three colors, red, green, blue, parallel to the different squares in each square. The luminance of these three colors is not necessarily equal. These three closely overlapping red, green, and blue rectangles are linked to the next square to form a sheet, which clearly shows a multicolored image.
Color TV reproduces colors in nature through three original colors red, green, and blue. Based on each person’s different preferences, we can adjust the magnitude of the saturation to change the saturation of the colors to match each person’s eye characteristics.