CCD camera parameters

Or pixel point or pixel size, refers to the actual size of a single sensing pixel, regardless of its length or width, which is measured in microns (microns). Refers to the actual physical size of each pixel on the chip pixel array, which usually includes 14 micron, 10 micron, 9 micron, 7.4 micron, 7 micron, 6.45 micron, 3.75 micron, etc. The larger the pixel size, the better the CCD quality. The pixel size reflects the chip's response to light to some extent. The larger the pixel size, the more photons can be received, and the more charges generated under the same lighting conditions and exposure time, the stronger and clearer the image information. For low light imaging, pixel size is a representation of chip sensitivity. The larger the pixel size, the better the chip sensitivity and the better the image quality of CCD imaging. If the resolution allows, choose a camera with a large pixel size, and the dynamic range will be larger; Larger pixel size will also improve the sensitivity of the camera (sensitivity refers to how dark the camera can work). The larger the pixel size, the better the CCD imaging quality and the higher the cost.

Charge coupled device

Individual photoelectric sensors (called pixels) are combined into a semiconductor device in the form of a matrix or a line. The optical lens focuses the image on this sensor, and each pixel accumulates a charge proportional to the light, and then transmits it for reading. The size of the output matrix is half that of the photosensitive element matrix, which is the interlaced mode CCD. If it is the same size, it is the progressive scanning CCD. When CCD/CMOS works normally, the number of charges output due to other factors besides the really effective output signal is called.

Quantum efficiency:

The ratio of the total number of photons directly entering or projecting on the sensor element to the number of charges converted by the sensor is usually expressed as a percentage (%).

Potential well capacity (falling well capacity)

The total amount of all charges contained in each pixel. The more numbers, the larger the dynamic range of the image; It can better represent any slight change in brightness on the image.

Signal to noise ratio:

Often expressed in dB, it is the noise ratio of normal signal output to electronic signal.

Analog to digital:

It is the format of image signal output by CCD/CMOS camera. The standard CCD/CMOS developed in the early days mostly used analog signal output, and then digital cameras with built-in analog-to-digital (ADC) circuits were introduced one after another. The gray scale of the image that the camera can provide depends on the number of bits in the A/D conversion circuit. For example, an 8-bit camera can provide a grayscale image output of 28=256, and 10 represents the grayscale expression of 1024, and so on. The greater the gain of signal amplification parameters, the shorter the exposure time, but the corresponding noise will also increase.