User`s manual

Camera Functional Description

Basler aviator Camera Link 41

3.1.2 One Sensor Tap Digitization Mode

With one tap sensor digitization, only one electronic circuit is used to read out the pixels in the

sensor (see Figure 17 on page 42). The advantage of the one tap digitization scheme is that it

eliminates the need to balance four different readout circuits as is required with four tap readout.

The drawback with one tap readout is that since it takes much longer to read out the sensor when

using one tap, the camera’s maximum achieveable frame rate is limited.

After a image has been captured (i.e., exposure has ended), the pixels in the sensor become ready

to be read out. At the start of readout, the charges accumulated during exposure are transported

from the pixels to the sensor’s vertical shift registers. The charges from the top line of pixels in the

array are then moved to the upper horizontal shift register as shown in Figure 17.

Next, the charges are moved out of the upper horizontal shift register. As the charges move out of

the horizontal shift register, they are converted to voltages proportional to the size of each charge.

Each voltage is then amplified by a Variable Gain Control (VGC) and digitized by an analog-to-

digital converter (ADC). For optimal digitization, gain and black level can be adjusted by setting

camera parameters.

After each voltage has been amplified and digitized, it passes through an FPGA and into an image

buffer. All shifting of charges from the vertical to the horizontal register and out of the horizontal

fashion until all image data has been read out of the sensor.

Once all of the pixel data has been read out of the imaging sensor and into the image buffer, the

data can begin being transmitted via the Camera Link interface to the frame grabber in your PC.

When the camera is set for one tap digitization, the 1X2-1Y "Camera Link tap geometry" must be

used to transmit the pixel data over the Camera Link interface to the frame grabber in your PC. For

more detailed information about tap geometries, see Section 6.2 on page 95.