Explanation of Measuring Principle
High-Speed Image Processing Circuit
The stripe light is scanned on the CCD image plane at one horizontal line per frame, and the CCD is driven so that the block readout start position is shifted one line per frame.
Approximately 600 frames are acquired.
·CCD drive rate: 12.5MHz
·Block readout: 125 lines
·Data acquisition speed: 2.5 sec.
The output signal from the CCD is then converted into a digital signal, which is then subjected to digital signal processing. The signal processed data is finally saved in the frame memory.
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| Frame |
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| Memory |
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Frame interline |
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Transfer CCD |
| A/D |
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| FIFO |
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| DSP |
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Clock Generator
Host I/F
Galvano
ScannerLaser
Diode
CPU
Driver
CPU Data Bus
Time center of gravity and Space center of gravity
Time center of gravity is the center of gravity of the variation in the LD light passing CCD’s one picture element over a period of time.
Space center of gravity is the center of gravity of the spatial variation in the LD light on the CCD at a certain time.
With this instrument, 3D images are obtained by calculating the Time center of gravity of each picture element of CCD. Intersection of the viewing angle of each picture element of the CCD and passing angle (time) of the stripe light is calculated.
Compared to the Space center of gravity, use of Time center of gravity can reduce influences of sensitivity variation of CCD’s picture elements and variation of brightness of the object.
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