This disclosure provides systems and methods for decoupling the mechanical drive systems of image scanners from the exposure system. A light source, such as an array of light-emitting diodes (LEDs), may be modulated in order to maintain a constant exposure for each scan-line, regardless of the document velocity. Accordingly, the present systems and methods allow for continuous document scanning at varying speeds. An automatic document feeder may dynamically adjust the velocity of a document without negatively impacting the exposure of the image scan. As the velocity of the document is changed, the modulation rate of the light source may be adjusted to maintain a constant exposure.
A zero reference and offset compensation circuit for an operational amplifier operating in the inverting mode in order to correct for both current and voltage offset errors. The zero reference and offset compensation circuit includes comparators for comparing the zero condition output of the operational amplifier with representations of lower and upper boundary signal levels, a pair of digital-to-analog converters having their respective analog outputs connected through appropriate scaling networks to the inverting input terminal and to the non-inverting input terminal of the operational amplifier, a microprocessor connected to the output of the comparators for providing an input to the associated digital-to-analog convertor so it produces an incremented digital signal whenever the comparators indicate the zero condition signal output exceeds either boundary signal level, the incremented digital signal being incremented in a direction to drive the associated digital-to-analog converter in a direction to bring said zero condition signal within the boundary which has been exceeded. The microprocessor has a current range selection capability so that the digital-to-analog converter connected to the inverting terminal is incremented for nanoampere range signal currents and the digital-to-analog converter associated with the non-inverting terminal is incremented for signal currents in the microampere range and above.
Youtube
Bustin at Raphael
This video was uploaded from an Android phone.
Duration:
46s
20140118 115758
Duration:
9s
20140118 114322
Duration:
25s
Rise of the TMNT Ninja Turtles Vehicles #Prim...
Vroom! Donnie has rolled out his latest inventionthe road-hoggin' vill...
Duration:
16s
Teenage Mutant Ninja Turtle Shell Hog Motorbi...
4 year old Kaio and Daddy unpack, play and review the Teenage Mutant N...
Duration:
9m 43s
Prison Horror Stories - The Real Truth About ...
Hey guys, Youtube deliberately does NOT promote my videos fairly. I wo...
Duration:
30m 13s
We were not expecting this much toys @ Gamest...
Join me to reach 500k subscribers my instagram Fan mail email me...
Duration:
32m 13s
Rene Amesz - Bustin' (Extended Mix)
Rene Amesz is back on Toolroom Trax and ready to get your body moving ...