Basic knowledge of CMOS Sensor

CMOS Parallel Sensor some basic knowledge

1S seconds = ms milliseconds = 1000_1000 US subtle = 1000_000_000 NS nanoseconds

1GHz = + MHz = 1000_000 KHz = 1000_000_000 Hz

The exposure time is in the president's unit; PCLK is in Hz;

The president takes the number of cycles, and the length of the frame is in the number of Presidents;

The T cycle is in MS, and F frequency is in Hz; f = 1/t; period and frequency are time units, but different forms of expression

Vsync = Dummy line = Vtotal = VTS = v_size + V_blank//frame length; Does not occupy the exposure time, but affects the frame rate (FPS)

Hsync = Dummy Pixel = htotal = HTS = h_size + H_blank//president; Increases exposure time and affects frame rate (FPS)

fps = PCLK/(VTS * HTS)//Calculate FPS

T_row = HTS/PCLK//Int_time equals 1, this formula represents the exposure time of a line.

EXP = T_row * Int_time//Int_time integration Time (exposure time Register)

1. The calculation of FPS can be achieved by modifying the v_total, h_total or reducing the PCLK frequency (when the HTS or VTS is lowered to the limit, it is necessary to reduce the PCLK to achieve the purpose of reducing the FPS) to achieve the purpose of reducing the frame.

2. Ob = Black level Dark Current

3. AE main control sensor EXP & Gain These two kinds of registers

4. Sensor comes with ISP,MIRROR,FLIP,WDR not to do a long explanation

CMOS MIPI Sensor

Look at the data line logarithm, you know, N Lane's sensor.

CMOS Sub-lvds Sensor

Look at the data line logarithm, you know, N Lane's sensor.

CMOS Hispi

Add:

Integration Time Integration

Flicker is not generated when the light source period is an integer multiple of integration time

Integration time is the point in the behavior unit of the exposure time (exposure times), such as int Tim is 159, refers to the sensor exposure time is 159 lines,
Both represent the same meaning of the sensor exposure, but integration time is a relative concept, that is, in the unit of behavior, and the absolute time per row is related to the PCLK clock frequency and the number of PCLK (that is, the President) each line contains. While exposure time refers to the absolute duration of sensor exposure, the relationship between the two conversions is as follows:
Exposure time = Integration Time x President/PCLK frequency

Light source cycle should be understood as the energy cycle of the light source, is twice times the alternating current cycle (such as the AC frequency is 50hz, the light source energy period is 0.01s), the absolute time of step is equal to the energy period of the light source.
Flicker There are two cases, one is the progressive reset integral generation, that is, intra-frame flicker, the display of the image of the phenomenon of alternating light and shade, mainly because a frame does not peer although the int Tim consistent, but because the starting point of the integration is not the same, And the luminous intensity of the indoor artificial light source and the frequency of alternating current are periodic relationship, resulting in different lines of the light amount is inconsistent, resulting in the phenomenon of alternating shading, and if a frame occupies time is not an integer multiple of the energy period of the light source, can observe the flicker instability, the relative position of the shading line is constantly changing, As if the dark line is moving upward, if the absolute time of a frame is guaranteed to be an integer multiple of the energy period of the light source, the filiker can be stabilized;
Another situation is the whole frame reset integral mode, that is, video browsing, the flicker between frames, that is, the different frames of light and dark inconsistencies, the current elimination method is by adjusting the GLB gain value to improve

GLB gain is the global gain, is to adjust the overall brightness of the image gain value, and r/b/g gain is used in the concept of AWB, for the three primary colors are adjusted separately, is to adjust the color offset