Weak current College】 【CCD working principle】.

<br> <br> <br> Ccd works compared to ccd and traditional film, ccd closer to the human eye on Visual work. However, the human eye's retina is responsible for the light intensity induction of rod cells and cone cells of color sensors ., the Division is composed of vision sensors. Ccd after 35 years of development, the approximate shape and operation have been finalized. Ccd's composition mainly by a similar mosaic of grid, condenser tablets and pad to the bottom of electronic circuit matrix. Currently has the .capacity to produce CCD company are: sony, matsushita philps, kodak, fuji, sanyo, sharp, and half of Japan and Thailand. Ccd's three-layer structure: Prism lenses: color grids: induction line <br> Decomposition can be found, ccd .structure to assist ccd to combine solid colour images, the grid was developed into a rule of the color matrix, these grid to red r, green g, and blue b filter plate consisting of (RGB ccd), a complementary color ccd (cmyg. .. Y-yellow). Each ccd elements from millions of mos capacitance forms (the amount of light points depends on draw-CCD). When digital camera shutter opens, from the image of light passing through these mosaic color will make the PC points of .silicon dioxide materials release electronic page <negative> and electric hole page <positive>. Join via an external voltage electronic and electric tunnel will be transferred to another different Polar silica layer staging. The size of the number of electrons and the exposure process light point .receives is proportional to the amount of light. In one of the brightest parts of images, there may be more than 10 000 electrons are accumulated. To the market common il-ccd, for example, exposure to all of charge after will be transferred to .the neighbouring shift register, and the successive line by line into the signal stream to read from the matrix. The strength of the signal will be sent a dsp is the digital imaging unit. In this unit which has an a / d converter analog digital signals .. The converter cannot apply a continuous range of signals with color codes distribution Pty, converted to a 2d plane represents series, it gives each picture element has a tonal values, the application of this method, and then by point grid, each point (art .-) now has used to indicate that it accepted the amount of light, of the binary data can be displayed strong or weak, eventually consolidated image output. <br> <br> Four types of ccd in response to the needs of different kinds of .work, the industry developed four different types of ccd: linear linear, interline scan, panoramic full-frame and frame-transfer biography. Linear ccd is a one-dimensional photosensitive dots, scan through stepping motor, because the photo is the image line by .line, therefore faster than using 2-dimensional CCD digital camera came slowly. Most of this type ccd scanner for the platform. Nterline scan type ccd exposure step (step 1.-See above) and is the same as described earlier, the difference lies .in the way of reading the charge. Interline ccd through vertical carousel (step 2) to read from scratch in a matrix, then down to the bottom level conversion logger (step 3), and then charge in moving to the amplifier (Orange Circle) ., then read the dsp in the horizontal position and finally produce electronic signal represents a complete digital imaging. Empty the register, and then reset the position in order to receive the next image. Il-the advantage of the ccd exposure to charge storage in the .register, the component can continue to shoot the next photo, therefore faster, the speed of reaction to have up to 15 photos per second or more. But the disadvantage of il is the staging area in occupies an area of a sensitive point, so the .dynamic range (dynamic range-the lightest and most system dark gaps between the extent of the performance). However, because of its speed, lower cost, so the market more than 86 percent of the digital camera with ccd-il-photographic elements. .Full-frame total like ccd is a framework simpler PC design. In view of the shortcomings of the il, you can use the entire ff improved photographic area (no staging area for design), effectively increasing the PC range, but also suitable for long .time exposure. The exposure process and the same, but the PC interline and charge output process is separate. Therefore, use ff CCD digital camera in the shipping charge information must be completely shut down the shutter to isolated lens incident light to prevent interference. This .also means that ff must use mechanical shutter (cannot use il e clock shutter), and also limits the ff CCD continuous shooting capability. Full-frame ccd mostly used at the top of the digital machine back. Ff ccd operation diagram <br> < .br> Frame-transfer biography CCD schema is from il and ff between products, it is divided into two parts, the upper part is a sensitive area, the lower section is temporarily store. Overall, ccd is very similar to frame-transfer full- .frame ccd, it is characterized by direct planning a large staging area. Once the ccd operation, it ft can quickly charge transfer to the bottom of the staging area, you can continue to expose themselves to take photographs. This design, like with il ft .can use electronic shutter, but also can increase the photosensitive area and speed. Ft ccd mainly by the philips company development of the Netherlands and later technology transferred to sanyo company develop into vpmix technology. Sanyo improvement on vpmix quite successful, make its digitalThe camera cannot .be both static and animated shooting capability (up to 30 fps shooting speed-use in the animation is excellent)..