Nikon L110 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Expeed C2 processor. On the other hand, Nikon L840 has a
16.0MP 1/2.3' (6.17 x 4.55 mm ) sized CMOS sensor .
Below you can see the L110 and L840 sensor size comparison.
Nikon L110 and Nikon L840 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Nikon L110 has 32% larger pixel area compared to Nikon L840, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.