Electronic – this “drive circuit” for CCD sensor referenced to

Some hints from experience:

• try to somehow to identify the CCD sensor and get the datasheet. Without that it will be very hard to do anything reasonable. The only work around would be to analyze live signals while the scanner is still working.
• try to reuse as much of the electronics as possible. E.g. level shifters, signal conditioning. Also the ADC may be reusable.

If you want some ideas about a project reusing a CCD line sensor have a look at this article which was published in the German Computer magazine c't or at the original project page (both in German).

The positive slope of the triangle wave needs twice the gain of the negative slope, this can't be done in an opamp and resistors circuit without some trick:

Signal s1 = triangle wave, 0 V to +4 V
Signal s2 = square wave, 0 V to +12 V
Signal s3 = s1/2 + s2/2, 0 V to +8 V

This is where the trick comes in. The triangle wave's slopes are symmetrical, and we need them different. Trick: use a rail-to-rail opamp with a \$\pm\$12 V supply. We'll use that to clip the top of the s3 waveform.

Signal s4 = 2 \$\times\$ s3 (clipped), 0 V to +12 V
Signal s5 = Vout = s4 - 8 V + s1, -8 V to +8 V

Schematic, just 2 opamps and 9 resistors: