Balluff MATRIX VISION mvBlueFOX Series, Техническое руководство, Страница: 186 / 238

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1.19.1.1.6 CCD Signal Processing
The CCD signal is processed with an analog front-end and digitized by an 12 bit analog-to-digital converter
(ADC). The analog front-end contains a programmable gain amplifier which is variable from 0db (gain=0) to 30dB
(gain=255).
The 8 most significant bits of the ADC are captured to the frame buffer. This will give the following transfer function
(based on the 8 bit digital code): Digital_code [lsb] = ccd_signal[V]
∗
256[lsb/V]
∗
exp(gain[bB]/20) lsb : least
significant bit (smallest digital code change)
Device Feature And Property List (p. 178 )
1.19.1.1.7 Device Feature And Property List
• mvBlueFOX-220G Features (p. 178 )
• mvBlueFOX-220C Features (p. 178 )
1.19.1.1.7.1 mvBlueFOX-220G Features
1.19.1.1.7.2 mvBlueFOX-220C Features
1.19.1.2 mvBlueFOX-[Model]220a (0.3 Mpix [640 x 480])
1.19.1.2.1 Introduction
The CCD sensor is a highly programmable imaging module which will, for example, enable the following type of
applications
Industrial applications:
• triggered image acquisition with precise control of image integration start by hardware trigger input.
• image acquisition of fast moving objects due to:
– frame integration, integrating all pixels at a time in contrast to CMOS imager which typically integrate
line-by-line.
– short shutter time, to get sharp images.
– flash control output to have enough light for short time.
Scientific applications:
• long time integration for low light conditions.
• optimizing image quality using the variable shutter control.
1.19.1.2.2 Details of operation
The process of getting an image from the CCD sensor can be separated into three different phases.
1.19.1.2.2.1 Trigger
When coming out of reset or ready with the last readout the CCD controller is waiting for a Trigger signal.
The following trigger modes are available:
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