Ricoh CX4 has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Smooth Imaging Engine IV processor. On the other hand, Panasonic TS20 has a
16.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Panasonic TS20's sensor provides 6MP more than Ricoh CX4's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the CX4 and TS20 sensor size comparison.
Sensor Size and Resolution Comparison image of Ricoh CX4 and Panasonic TS20 Cameras
Ricoh CX4 and Panasonic TS20 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Ricoh CX4
or the
Panasonic TS20 ,
including hyperfocal distance.