BOBCAT HD-SDI
Hardware User’s Manual
Imperx, Inc.
Rev. 1.4
6421 Congress Ave.
6/2/2014
Boca Raton, FL 33487
+1 (561) 989-0006
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1.3.
BOBCAT HD-SDI SPECIFICATIONS
1.3.1.
General Information
A CCD camera is an electronic device for converting light into an electrical
signal. The camera contains a light sensitive element CCD (Charge Coupled
Device) where an electronic representation of the image is formed. The CCD
consists of a two dimensional array of sensitive elements – silicon photodiodes,
also known as pixels. The photons falling on the CCD surface create
photoelectrons within the pixels, where the number of photoelectrons is linearly
proportional to the light level. Although the number of electrons collected in
each pixel is linearly proportional to the light level and exposure time, the
amount of electrons varies with the wavelength of the incident light. When the
desired exposure is reached, the charges from each pixel are shifted onto a
vertical register, VCCD, and then one row downwards in a vertical direction
towards a horizontal register, HCCD. After that the electrons contained in the
HCCD are shifted in a horizontal direction, one pixel at a time, onto a floating
diffusion output node where the transformation from charge to voltage takes
place. The resultant voltage signal is buffered by a video amplifier and sent to
the corresponding video output. There are two floating diffusions and two video
amplifiers at each end of the HCCD, and the charges can be transferred towards
any of the outputs (depending on the mode of operation). The time interval
required for all the pixels, from the entire imager, to be clocked out of the HCCD
is called a frame. To generate a color image a set of color filters (Red, Green, and
Blue) arranged in a “Bayer” pattern, are placed over the pixels. The starting color
is typically Green for TRUESENSE CCDs and Red for SONY CCDs, but it
varies from CCD to CCD. Figure 1.1 shows the CCD pixel structure. Table 1.2
shows the individual pixel structure for different BOBCAT HD-SDI cameras.
Effective pixels image consists of Active and Buffer pixels. Figures 1.2-6 show
the camera’s spectral response. Figure 1.7 shows the Bayer pattern arrangement.
